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

0,2

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).

Links

Table of n, a(n) for n=0..17.

Prog

(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)}

Crossrefs

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

Sequence in context: A371743 A208812 A291103 * A367752 A254124 A203970

Adjacent sequences: A125805 A125806 A125807 * A125809 A125810 A125811

Keyword

nonn

Author

Paul D. Hanna, Dec 12 2006

Status

approved