A091260 Denominator of sigma_3(n)/sigma_2(n).

1, 5, 5, 21, 13, 25, 25, 17, 91, 65, 61, 15, 85, 125, 65, 11, 145, 455, 181, 13, 125, 305, 265, 85, 651, 425, 41, 525, 421, 325, 481, 455, 305, 725, 325, 1911, 685, 181, 425, 17, 841, 625, 925, 427, 169, 1325, 1105, 55, 817, 1085, 725, 255, 1405, 205, 793, 425, 181

Offset

1,2

Comments

If n is an odd prime then a(n) = A001844((n-1)/2). - Robert Israel, Jan 26 2018

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Maple

seq(denom(numtheory:-sigma[3](n)/numtheory:-sigma[2](n)), n=1..100); # Robert Israel, Jan 26 2018

Mathematica

Denominator[Table[DivisorSigma[3, n]/DivisorSigma[2, n], {n, 60}]] (* Harvey P. Dale, Nov 03 2011 *)

Crossrefs

Cf. A001158, A001157, A000203, A091258, A091259, A298754, A001844.

Sequence in context: A255446 A255450 A127513 * A352315 A283212 A283250

Adjacent sequences: A091257 A091258 A091259 * A091261 A091262 A091263

Keyword

easy,nonn,frac

Author

Labos Elemer, Feb 12 2004

Status

approved