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A369622 Expansion of (1/x) * Series_Reversion( x / (1/(1-x)^2 + x^3) ). 2
1, 2, 7, 31, 151, 783, 4243, 23740, 136099, 795321, 4719980, 28370532, 172357487, 1056658346, 6528779587, 40614467912, 254167595939, 1599012530917, 10107091256418, 64155246033712, 408780285886008, 2613634555525584, 16763436345211527, 107827070566159112 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(n+1,k) * binomial(3*n-5*k+1,n-3*k).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/(1/(1-x)^2+x^3))/x)
(PARI) a(n) = sum(k=0, n\3, binomial(n+1, k)*binomial(3*n-5*k+1, n-3*k))/(n+1);
CROSSREFS
Sequence in context: A076177 A335868 A126033 * A323632 A369265 A369297
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 27 2024
STATUS
approved

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Last modified July 23 21:46 EDT 2024. Contains 374575 sequences. (Running on oeis4.)