

A134339


a(n) = product of the positive "nonisolated divisors" of (2n). A divisor, k, of n is nonisolated if (k1) or (k+1) also divides n.


1



2, 2, 6, 2, 2, 24, 2, 2, 6, 40, 2, 24, 2, 2, 180, 2, 2, 24, 2, 40, 252, 2, 2, 24, 2, 2, 6, 112, 2, 720, 2, 2, 6, 2, 2, 1728, 2, 2, 6, 40, 2, 1008, 2, 2, 16200, 2, 2, 24, 2, 40, 6, 2, 2, 24, 220, 112, 6, 2, 2, 720, 2, 2, 252, 2, 2, 3168, 2, 2, 6, 40, 2, 1728, 2, 2, 180, 2, 2, 3744, 2, 40, 6
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OFFSET

1,1


COMMENTS

No odd integer has any nonisolated divisors.


LINKS

Table of n, a(n) for n=1..81.


FORMULA

a(n) = A007955(2n) / A134338(2n).  Chandler


EXAMPLE

The divisors of 2*10 = 20 are 1,2,4,5,10,20. Of these, 1,2,4,5 are the nonisolated divisors. So a(10) = 1*2*4*5 = 40.


CROSSREFS

Cf. A134338.
Sequence in context: A126889 A205030 A278250 * A162299 A281552 A205506
Adjacent sequences: A134336 A134337 A134338 * A134340 A134341 A134342


KEYWORD

nonn


AUTHOR

Leroy Quet, Oct 21 2007


EXTENSIONS

Extended by Ray Chandler, Jun 24 2008


STATUS

approved



