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 A369506 Expansion of (1/x) * Series_Reversion( x / ((1+x)^3+x^2)^2 ). 0
 1, 6, 53, 548, 6192, 74074, 922142, 11822082, 155024190, 2069570934, 28033435791, 384329462490, 5322745393480, 74357950874850, 1046564375245893, 14826433687124098, 211251475010201934, 3025331234242178508, 43523061969049245589, 628692982662691174722 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..19. Index entries for reversions of series FORMULA a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} binomial(2*n+2,k) * binomial(6*n-3*k+6,n-2*k). PROG (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/((1+x)^3+x^2)^2)/x) (PARI) a(n) = sum(k=0, n\2, binomial(2*n+2, k)*binomial(6*n-3*k+6, n-2*k))/(n+1); CROSSREFS Cf. A143927, A369503. Sequence in context: A055973 A223345 A362907 * A066357 A276365 A185148 Adjacent sequences: A369503 A369504 A369505 * A369507 A369508 A369509 KEYWORD nonn AUTHOR Seiichi Manyama, Jan 25 2024 STATUS approved

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Last modified July 17 05:48 EDT 2024. Contains 374360 sequences. (Running on oeis4.)