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A371369
Expansion of (1/x) * Series_Reversion( x * (1-8*x)^2 / (1-7*x) ).
0
1, 9, 161, 3593, 89729, 2399817, 67222433, 1946874569, 57824172545, 1751650872713, 53910484818849, 1680961253003401, 52987626458710657, 1685806021244435913, 54062032254640697505, 1745723303156237416265, 56713604222408801019905
OFFSET
0,2
FORMULA
a(n) = (1/(n+1)) * Sum_{k=0..n} 7^(n-k) * binomial(2*n+k+1,k) * binomial(2*n,n-k).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serreverse(x*(1-8*x)^2/(1-7*x))/x)
(PARI) a(n) = sum(k=0, n, 7^(n-k)*binomial(2*n+k+1, k)*binomial(2*n, n-k))/(n+1);
CROSSREFS
Cf. A082147.
Sequence in context: A337627 A020523 A023039 * A243682 A367160 A337152
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 19 2024
STATUS
approved