A143968 - OEIS

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A143968

Denominators of numbers with g.f. exp(1-(1-x)^(1/2)).

1, 2, 4, 48, 384, 1920, 46080, 645120, 5160960, 185794560, 530841600, 40874803200, 280284364800, 51011754393600, 714164561510400, 42849873690624000, 1371195958099968000, 302731575164928000, 1678343852714360832000, 100120983364435968000, 1275541328062914232320000

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Robert Israel, Table of n, a(n) for n = 0..406

EXAMPLE

1, 1/2, 1/4, 7/48, 37/384, 133/1920, 2431/46080, 27007/645120, 176761/5160960, ...

MAPLE

S:= series(exp(1-(1-x)^(1/2)), x, 21):

seq(denom(coeff(S, x, i)), i=0..20); # Robert Israel, Mar 23 2023

MATHEMATICA

CoefficientList[Series[Exp[1-Sqrt[1-x]], {x, 0, 20}], x]//Denominator (* Harvey P. Dale, Sep 13 2019 *)