A126192 - OEIS

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A126192

Product of the even divisors of 2n.

2, 8, 12, 64, 20, 576, 28, 1024, 216, 1600, 44, 110592, 52, 3136, 3600, 32768, 68, 373248, 76, 512000, 7056, 7744, 92, 84934656, 1000, 10816, 11664, 1404928, 116, 207360000, 124, 2097152, 17424, 18496, 19600, 5159780352, 148, 23104, 24336, 655360000, 164

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OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = 2^A000005(n) * A007955(n). - Robert Israel, Feb 01 2019

MAPLE

seq(mul(2*t, t=numtheory:-divisors(n)), n=1..100); # Robert Israel, Feb 01 2019

MATHEMATICA

Table[Times@@Select[Divisors[2n], EvenQ], {n, 50}] (* Harvey P. Dale, Jul 19 2011 *)

a[n_] := 2^(d = DivisorSigma[0, n]) * n^(d/2); Array[a, 100] (* Amiram Eldar, Jun 26 2022 *)