login
A372017
G.f. A(x) satisfies A(x) = ( 1 + 9*x/(1 - x*A(x)) )^(1/3).
1
1, 3, -6, 39, -213, 1425, -9681, 69393, -509307, 3827856, -29254443, 226787682, -1778491446, 14084085711, -112462798281, 904485811944, -7319902809228, 59565238152789, -487071807495099, 4000169922457260, -32980470088198209, 272875134913543488
OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} 9^k * binomial(n/3-k/3+1/3,k) * binomial(n-1,n-k)/(n-k+1).
PROG
(PARI) a(n) = sum(k=0, n, 9^k*binomial(n/3-k/3+1/3, k)*binomial(n-1, n-k)/(n-k+1));
CROSSREFS
Cf. A372003.
Sequence in context: A172361 A114038 A000222 * A208649 A371063 A203178
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 15 2024
STATUS
approved