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A377263
Expansion of (1 - 9*x*(1 - 9*x)^(2/3))^(2/3).
0
1, -6, 27, 126, 513, 1296, -1782, -35964, -68526, 2131110, 31341168, 257694210, 1423944765, 4790619126, 5675652099, 61932520134, 2351897164665, 36303263670942, 365306247890865, 2733496597694394, 16050141707838840, 82517222301874110, 544262710381797330
OFFSET
0,2
FORMULA
a(n) = 9^n * Sum_{k=0..n} (-1)^k * binomial(2/3,k) * binomial(n-5*k/3-1,n-k).
PROG
(PARI) a(n) = 9^n*sum(k=0, n, (-1)^k*binomial(2/3, k)*binomial(n-5*k/3-1, n-k));
CROSSREFS
Cf. A377244.
Sequence in context: A030297 A045500 A360057 * A109115 A038176 A104745
KEYWORD
sign
AUTHOR
Seiichi Manyama, Oct 22 2024
STATUS
approved