A385475 - OEIS

A385475

Expansion of (1/x) * Series_Reversion( x * (1-2*x)^3 / (1+x)^4 ).

1, 10, 154, 2836, 57601, 1244584, 28063288, 652821724, 15551944804, 377503375150, 9303441938506, 232168129150420, 5854967533764766, 148981015820615968, 3820184959840942564, 98616983735455104412, 2560818171703792341484, 66845502538144505160040

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

Index entries for reversions of series

FORMULA

a(n) = (1/(n+1)) * Sum_{k=0..n} 2^(n-k) * binomial(4*(n+1),k) * binomial(4*n-k+2,n-k).

a(n) = (1/(n+1)) * [x^n] ( (1+x)^4 / (1-2*x)^3 )^(n+1).

PROG

(PARI) my(N=20, x='x+O('x^N)); Vec(serreverse(x*(1-2*x)^3/(1+x)^4)/x)

(PARI) a(n) = sum(k=0, n, 2^(n-k)*binomial(4*(n+1), k)*binomial(4*n-k+2, n-k))/(n+1);

CROSSREFS

Cf. A064063, A385474.

Cf. A386723.

Sequence in context: A048907 A061654 A298081 * A240374 A261744 A229284

Adjacent sequences: A385472 A385473 A385474 * A385476 A385477 A385478

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Aug 01 2025

STATUS

approved