OFFSET
0,2
FORMULA
a(n)=sum(A112692(k, m), m=0..((k+1)*(k+2)/2)-1), k>=0.
Let A(x)=sum(k>=0, |a(k)|*x^k ), then A(x)= G(0)/(4*x)- 1/(2*x), where G(k)= 1 + 1/(1 - 2*x*(2*k+1)!/(2*x*(2*k+1)! + 1/(1 + 1/(1 - 2*x*(2*k+2)!/(2*x*(2*k+2)! + 1/G(k+1) ))))); (continued fraction). - Sergei N. Gladkovskii, Jul 10 2013
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang, Oct 14 2005
STATUS
approved