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A020930 Expansion of 1/(1-4*x)^(19/2). 3
1, 38, 798, 12236, 152950, 1651860, 15967980, 141430680, 1166803110, 9075135300, 67156001220, 476197099560, 3254013513660, 21526550936520, 138384970306200, 867212480585520, 5311676443586310, 31870058661517860 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

FORMULA

a(n)=binomial(n+9, 9)*A000984(n+9)/A000984(9), where A000984 are the central binomial coefficients. - Wolfdieter Lang

a(n) = ((2*n+17)*(2*n+15)*(2*n+13)*(2*n+11)*(2*n+9)*(2*n+7)*(2*n+5)*(2*n+3)*(2*n+1)/34459425)*Binomial(2*n, n). - Vincenzo Librandi, Jul 05 2013

Boas-Buck recurrence: a(n) = (38/n)*Sum_{k=0..n-1} 4^(n-k-1)*a(k), n >= 1, a(0) = 1. Proof from a(n) = A046521(n+9, 9). See a comment there. - Wolfdieter Lang, Aug 10 2017

MATHEMATICA

CoefficientList[Series[1 / (1 - 4 x)^(19/2), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 05 2013 *)

PROG

(MAGMA) [&*[2*n+i: i in [1..17 by 2]]*Binomial(2*n, n)/34459425: n in [0..20]]; // Vincenzo Librandi, Jul 05 2013

CROSSREFS

Cf. A000984, A020928, A046521 (tenth column).

Sequence in context: A162392 A010990 A004420 * A104761 A270500 A268788

Adjacent sequences:  A020927 A020928 A020929 * A020931 A020932 A020933

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified March 20 21:49 EDT 2019. Contains 321352 sequences. (Running on oeis4.)