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A299428 a(n) = binomial((n+1)*(2*n+1), n) * (n+1)/(2*n+1). 3
1, 4, 63, 1872, 82775, 4874688, 358919022, 31726703424, 3273365223135, 386120802767700, 51255818495200660, 7561964058268969440, 1227474574989496660008, 217398508335873934190800, 41718377034325560258265500, 8622580886584109407750765824, 1909661474657747399115123743055, 451173386162679212279972033149500 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Main diagonal of square table A299427.

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..310

FORMULA

a(n) ~ 2^(n - 3/2) * exp(n + 5/4) * n^(n - 1/2) / sqrt(Pi). - Vaclav Kotesovec, Feb 19 2018

PROG

(PARI) {a(n) = binomial((n+1)*(2*n+1), n) * (n+1)/(2*n+1)}

for(n=0, 20, print1(a(n), ", "))

CROSSREFS

Cf. A299427, A299429.

Sequence in context: A177788 A293860 A349075 * A274392 A237644 A024256

Adjacent sequences:  A299425 A299426 A299427 * A299429 A299430 A299431

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Feb 19 2018

EXTENSIONS

a(15) corrected by Seiichi Manyama, Feb 10 2019

STATUS

approved

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Last modified May 28 02:55 EDT 2022. Contains 354110 sequences. (Running on oeis4.)