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A280655 Numerator of Sum_{k=0..n^2-1}((-1)^k*sqrt(Pi)/(Gamma(1/2-k)*Gamma(1+k)))-n). 2
0, 3, 11091, 32104739, 43189424229655, 110209500084824275641, 17401090686295157740521962087, 1341749054684714449837337405947519267, 416437630008271514606815213642830281374740126189, 31880038884855523088456476438831355463732624957105297113285 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) has at most n prime factors.

LINKS

Table of n, a(n) for n=1..10.

FORMULA

a(n)=Numerator of Sum_{k=0..n^2-1}(Binomial(2k,k)/4^k)-n.

MATHEMATICA

Numerator[Table[Sum[Binomial(2k, k)/4^k, {k, 0, n^2-1}]-n, {n, 1, 10}]]

CROSSREFS

Cf. A280656 (denominators), A285388.

Sequence in context: A242865 A280300 A171363 * A262651 A309246 A055379

Adjacent sequences:  A280652 A280653 A280654 * A280656 A280657 A280658

KEYWORD

nonn,frac

AUTHOR

Ralf Steiner, Apr 12 2017

STATUS

approved

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Last modified November 28 22:15 EST 2021. Contains 349415 sequences. (Running on oeis4.)