A037198 Number of divisors of (sigma(n)-n) = number of divisors of n.

6, 9, 10, 14, 22, 28, 30, 33, 38, 42, 46, 51, 54, 60, 62, 66, 69, 84, 86, 87, 91, 92, 93, 96, 102, 118, 132, 133, 135, 141, 142, 145, 158, 159, 166, 168, 170, 174, 182, 183, 188, 190, 206, 216, 217, 219, 246, 247, 248, 249, 253, 262, 264, 267, 278, 280, 285, 290

Offset

1,1

Links

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

Mathematica

Select[Range[400], DivisorSigma[0, DivisorSigma[1, #]-#]==DivisorSigma[ 0, #]&] (* Harvey P. Dale, Feb 24 2017 *)

Prog

(PARI) isok(n) = (diff = sigma(n)-n) && (numdiv(n) == numdiv(diff)) \\ Michel Marcus, Jul 14 2013

Crossrefs

Sequence in context: A145311 A363464 A328244 * A359277 A054020 A121014

Adjacent sequences: A037195 A037196 A037197 * A037199 A037200 A037201

Keyword

easy,nonn

Author

Naohiro Nomoto

Status

approved