OFFSET
0,3
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..300
FORMULA
a(n) == 1 (mod 4).
Limit A222080(n)/a(n) = 2.
EXAMPLE
G.f.: A(x) = 1 + x + 5*x^2 + 41*x^3 + 453*x^4 + 6205*x^5 + 100649*x^6 +...
where
A(x)^2 = 1 + 2*x + 11*x^2 + 92*x^3 + 1013*x^4 + 13726*x^5 + 219919*x^6 +...+ A222080(n)*x^n +...
such that A222080 satisfies:
1 = (1-x)^2 + 2*x*(1-3*x)^2 + 11*x^2*(1-5*x)^2 + 92*x^3*(1-7*x)^2 + 1013*x^4*(1-9*x)^2 + 13726*x^5*(1-11*x)^2 + 219919*x^6*(1-13*x)^2 +...+ A222080(n)*x^n*(1 - (2*n+1)*x)^2 +...
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Feb 07 2013
STATUS
approved