A125808 Adjacent-to-central terms of even-indexed rows of triangle A125806: a(n) = A125806(2n+2,n).

1, 4, 29, 256, 2592, 28160, 322873, 3850352, 47369432, 597565304, 7695966346, 100852014156, 1341310032320, 18067954497864, 246098396499471, 3384883529933828, 46960152641672616, 656538880287562528

Offset: 0

Author

Paul D. Hanna, Dec 12 2006

Keywords

• nonn

Comments

Central terms of even-indexed rows of triangle A125806 equal A063075 (number of partitions of 2n^2 whose Ferrers-plot fits within a 2n X 2n box and cover an n X n box).

Crossrefs

Cf. A125806 (triangle); A063075; A125807, A125809 (row sums).

Programs

PARI

{a(n)=local(C_q=if(n==0,1,prod(j=n+3,2*n+2,1-q^j)/prod(j=1,n,1-q^j))); sum(i=0,(n+2)*n,polcoeff(C_q,i)^2)}