RESEARCH / Focused target
Kok's maximum degree and literal A319433 deletion
RELEASED FOUNDATIONS / PROPOSED CONNECTION
Research connections
All source anchors (1)
- D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.resultAbsent from this graph
Problem
The question
Johan Kok, Integer sequences with conjectured relation with certain graph parameters of the family of linear Jaco graphs, arXiv:2507.16500v1, Section 2.2, Conjecture 2.2, states:
For the finite linear Jaco graphs J_{n}(x), n=2,3,4,\dots the respective maximum degrees \Delta(J_{n}(x)) are yielded by the sequence A319433 with closed formula \Delta(J_{n}(x))=\lfloor\frac{2(n+2)}{1+\sqrt{5}}\rfloor-1, n=2,3,4,\dots
Furthermore, it implies that sequence A319433 is p-graphical where p(G)=\Delta(G) and \mathcal{F}={G:G=J_{n}(x),n=1,2,3,\dots}.
The formal graph is the underlying simple undirected graph of the finite
directed linear Jaco graph with f(x)=x. For vertices v_i, 1 ≤ i ≤ n,
write d_i for the number of earlier vertices v_k satisfying
2*k-d_k ≥ i; for i < j ≤ n, the directed arc (v_i,v_j) exists exactly
when 2*i-d_i ≥ j. J_n(x) forgets orientation and Delta is its ordinary
maximum degree.
The sequence term uses its actual offset-zero index. For n > 0, write the
canonical Zeckendorf representation with weights Fib_2=1, Fib_3=2, and no
consecutive occupied positions. Delete the digit position of weight Fib_2,
whether its digit is one or zero: remove occupied index 2 if present, lower
every surviving occupied index by one, and decode in the same Fibonacci
system. Call the result
a(n)=deleteLeast(n), with a(0)=a(1)=0.
The complete assertion is
$$ \left(\forall n\in\mathbb N,;2\le n\Rightarrow \left(\Delta(J_n(x))=\left\lfloor\frac{2(n+2)}{1+\sqrt5}\right\rfloor-1 \land\Delta(J_n(x))=a(n)\right)\right) \land \left(\forall n\in\mathbb N,;1\le n\Rightarrow \Delta(J_n(x))=a(n)\right). $$
The second conjunct retains the singleton J_1(x), whose degree and deletion
value are both zero. The first conjunct starts at n=2, exactly as in the
source. The index-zero sequence term is not reassigned to J_1; no J_0,
offset shift, order cutoff, subsequence, changed graph, or extra premise is
included.
Motivation
Our foothold
The theorem supplies a complete all-order resolution of the two clauses in
Conjecture 2.2 for the source's actual recursive graph and sequence indexing.
The fixed family {J_n(x) : n ≥ 1} therefore realizes every positive-index
term and every positive finite prefix under p(G)=Delta(G).
Gap
Missing bridges
The source presents the statement as a conjecture. The accepted formal delivery closes its universal graph and sequence assertions; finite tables, the source's earlier graph results, and the bounded literature screen are not used as substitutes for the Lean proof. Literature completeness, priority, and worldwide non-settlement remain outside this dossier's evidence.
Route
Proposed approach
JacoEndpointBeatty.endpoint_recurrence identifies the actual recursive
endpoint array, and endpoint_eq_beatty proves its all-order golden Beatty
law. JacoMaximumDegree.degree_formula counts the actual incoming and
outgoing neighbor intervals. The deletion-block bridge identifies the literal
Zeckendorf deletion with the attained maximum, and
max_degree_eq_deletion proves the positive-order family, including the
singleton. The public result combines the floor formula for every n ≥ 2
with the same-index deletion identity and the full n ≥ 1 family clause.
The deletion definitions in D5/S1/Words/Powers/ZeckendorfDeletion are a
consumed helper on the live path to result; that module is not presented as
an independent resolution of this problem.
Falsifier
What would falsify this route
A falsifier would be a positive order for which the encoded recursive Jaco
graph has a maximum degree different from either the displayed floor value or
the literal same-index deletion. A mismatch in the graph carrier, a shift of
the sequence offset, or omission of the singleton would also falsify the
source-faithful interpretation. The kernel-checked result discharges these
possibilities for the stated definitions and quantifiers.
Evidence
Evidence to collect
The settling declaration is
D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.result, whose exact
statement is the conjunction displayed above. Its owning Blueprint Scribe
contains the single typed OpenProblemResolutionClaim with resolution
Proved for this dossier. The corresponding source note is
Library/Certificates/kok2025jaco.md,
which records the verified locator
https://arxiv.org/html/2507.16500v1#S2.Thmtheorem2 (Conjecture 2.2),
the DOI, and the original A319433/A014417 sequence attribution.
The unchanged D5/Reg sources carry the proof terms; the accepted scoped Lean report supplies the standard axiom-closure and current-binding evidence. Canonical frozen states record statement IDs and declaration name/kind lists. No new Lean declaration, axiom, or reproof is introduced by this dossier. The four-slot audit boundary for the accepted delivery is:
| Target | Current audit state |
| --- | --- |
| D5/S1/Words/Powers/ZeckendorfDeletion.deletion_block | declared_validated |
| D5/S3/ConceptDynamics/GraphColoring/JacoEndpointBeatty.beatty_bounds | declared_validated |
| D5/S3/ConceptDynamics/GraphColoring/JacoEndpointBeatty.beatty_threshold | declared_validated |
| D5/S3/ConceptDynamics/GraphColoring/JacoEndpointBeatty.endpoint_eq_beatty | declared_validated |
| D5/S3/ConceptDynamics/GraphColoring/JacoEndpointBeatty.endpoint_recurrence | declared_unresolved — forbidden Nat.decLe dependency; issue #25698, comment 6582601274 |
| D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.degree_formula | declared_unresolved — forbidden Nat.decLt dependency; issue #25698, comment 6582601274 |
| D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.max_degree_eq_deletion | declared_unresolved — forbidden Nat.decLt dependency; issue #25698, comment 6582601274 |
| D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.result | registration remains unfinished; no false validation is asserted |
The unresolved continuation is unknown and supplies no missing source law.
These audit readings do not change the mathematical statement or its kernel
proof.
Triage
Scope assessment
Proved: JacoMaximumDegree.result proves both source clauses for the
actual finite recursive Jaco graphs and literal A319433 deletion. The Scribe
claim is attached only to this complete result. The endpoint and degree
lemmas are proof components, and the Zeckendorf deletion module is a consumed
helper rather than a second problem resolution.
Proved structure: The recursive endpoint law connects the graph construction to the Beatty description. Incoming and outgoing neighbor intervals give the vertex degrees, and the attainment argument supplies a vertex meeting the maximum-degree bound. The deletion bridge therefore identifies an attained maximum, rather than only an upper bound. The positive-order identity also settles the source's dependent p-graphical clause, including the singleton and every positive finite prefix.
Unresolved extensions: The result does not settle other graph parameters or other Jaco defining functions. Extending this route requires an endpoint law, a neighbor-counting formula and an attainment argument for the proposed family; no such extension or further source-conjecture consequence is proved here.
The source is a mathematical application of the cited article and OEIS sequence. Attribution is retained; code licensing is not asserted.
ASSUMED-UNVERIFIED
Unverified assumptions
The literature and ownership checks are bounded to the source note and the
surfaces recorded there. They do not establish exhaustive priority,
worldwide openness, publisher status, or legal-code licensing. Four audit
targets remain unfinished in total: the three declared_unresolved targets
and the aggregate result without registration, under the linked issue
exception #25698, comment 6582601274.
The unknown continuation is not a
claim of undecidability or inexhaustibility.