Combinatorics / CONCEPT

Two-layer solid partitions with a second layer of size 3

The two-layer solid partitions whose first layer is a plane partition of n and whose second layer is a plane partition of 3 number 3(2 A000219(n) - A000990(n) - 2 A000041(n) + 1), with A000219 the plane partitions, A000990 the plane partitions with at most two rows and A000041 the partitions of n, as conjectured by W. Meeussen for OEIS A381265.