A226479 Numbers n such that (sopf(n)*d(n))^2 = sigma(n) where sopf(n) = sum of distinct prime factors of n (A008472) and d(n) = number of divisors of n.

22446139, 26116291, 28097023, 30236557, 31090489, 31124341, 39618558, 41628195, 49941589, 51777957, 61137673, 62224039, 66960589, 71096795, 71334867, 71585139, 72304400, 82266591, 83045869, 92346023, 92837591, 105183961, 114762567, 117908994, 123563821

Offset

1,1

Comments

Suggested by N. J. A. Sloane.

Links

Donovan Johnson, Table of n, a(n) for n = 1..1000

Example

n = 22446139 = 31*67*101*107. sopf(n) = 31+67+101+107 = 306. d(n) = 16. (sopf(n)*d(n))^2 = (306*16)^2 = 23970816 = sigma(n).

Crossrefs

Cf. A000005, A000203, A006532, A008472, A126028, A226480.

Sequence in context: A022211 A331358 A046397 * A126028 A226480 A238154

Adjacent sequences: A226476 A226477 A226478 * A226480 A226481 A226482

Keyword

nonn

Author

Donovan Johnson, Jun 09 2013

Status

approved