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A037239 Numerator of Pi^(2n)/(GAMMA(2n)*(1-2^(-2n))*Zeta(2n)); = 8*(highest power of 2 dividing n). 1
8, 16, 8, 32, 8, 16, 8, 64, 8, 16, 8, 32, 8, 16, 8, 128, 8, 16, 8, 32, 8, 16, 8, 64, 8, 16, 8, 32, 8, 16, 8, 256, 8, 16, 8, 32, 8, 16, 8, 64, 8, 16, 8, 32, 8, 16, 8, 128, 8, 16, 8, 32, 8, 16, 8, 64, 8, 16, 8, 32, 8, 16, 8, 512, 8, 16, 8, 32, 8, 16, 8, 64, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..73.

Harvey Cohn, Some elementary aspects of modular functions in several variables, Bull. Amer. Math. Soc. 71 (1965), 681-704, (esp. p. 688).

MAPLE

with(numtheory): for n from 1 to 200 do if n mod 2 = 1 then printf(`%d, `, 8) else printf(`%d, `, 8*2^ifactors(n)[2][1][2]) fi; od:

seq(2^(3+padic[ordp](n, 2)), n=1..73); # Peter Luschny, Apr 03 2014

MATHEMATICA

a[n_] := 8*BitAnd[n, -n]; Table[a[n], {n, 1, 81}] (* Jean-Fran├žois Alcover, Sep 20 2011, after Joerg Arndt *)

PROG

(PARI) a(n)=if(n<1, 0, 8*2^valuation(n, 2))

CROSSREFS

Equals 8*A006519. Denominators given by A002425.

Sequence in context: A073925 A053321 A174256 * A205869 A217178 A103699

Adjacent sequences:  A037236 A037237 A037238 * A037240 A037241 A037242

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from James A. Sellers, Jun 20 2000

STATUS

approved

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Last modified December 12 16:18 EST 2017. Contains 295939 sequences.