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A366980
G.f. satisfies A(x) = 1 + x*A(x)^5 * (1 - x*A(x)).
0
1, 1, 4, 24, 171, 1336, 11060, 95298, 845649, 7675398, 70921457, 664905445, 6309060313, 60473691666, 584684295383, 5695312881404, 55839455579659, 550621231581791, 5457218248143692, 54332533436452743, 543148496962279730, 5449742750024662824
OFFSET
0,3
FORMULA
a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n+4*k+1,k) * binomial(k,n-k)/(n+4*k+1).
PROG
(PARI) a(n) = sum(k=0, n, (-1)^(n-k)*binomial(n+4*k+1, k)*binomial(k, n-k)/(n+4*k+1));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 01 2023
STATUS
approved