OFFSET
1,9
FORMULA
From Peter Bala, Jan 31 2021: (Start)
G.f.: A(q) = Sum_{n >= 0} q^(4*n+1) * Product_{k >= 2*n+1} 1 + q^(2*k+1).
A(q) = Limit_{N -> oo} Sum_{n = 0..2*N+1} (-1)^n * Product_{k = n..2*N+1} 1 + q^(2*k+1) = Limit_{N -> oo} Sum_{n = 0..2*N+1} (-1)^n * Product_{k >= n} 1 + q^(2*k+1). (End)
MAPLE
G := add( q^(4*n+1)*mul( 1 + q^(2*k+1), k = 2*n+1..50 ), n = 0..25 ):
S := series(G, q, 101):
seq(coeff(S, q, j), j = 1..100); # Peter Bala, Jan 31 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved