A139316 An integer k, k>=2, is in the sequence if A001222(k) (the sum of the exponents in the prime factorization of k) divides A008472(k) (the sum of the distinct primes dividing k).

2, 3, 4, 5, 7, 11, 13, 15, 17, 19, 21, 23, 27, 28, 29, 31, 33, 35, 37, 39, 41, 42, 43, 47, 48, 51, 52, 53, 55, 57, 59, 61, 65, 67, 69, 71, 72, 73, 76, 77, 78, 79, 83, 84, 85, 87, 89, 91, 93, 95, 97, 98, 101, 103, 105, 107, 108, 109, 110, 111, 113, 114, 115, 119, 120, 123

Offset: 1

Author

Leroy Quet, Jun 07 2008

Keywords

• nonn

Examples

			28 has the prime factorization 2^2 * 7^1. The sum of the exponents, 2+1 = 3, divides the sum of the distinct prime divisors, 2+7 = 9. So 28 is in the sequence.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001222, A008472.

Programs

Mathematica

seddpQ[n_]:=Module[{fi=Transpose[FactorInteger[n]]},Divisible[Total[ fi[[1]]],Total[ fi[[2]]]]]; Select[Range[2,150],seddpQ] (* Harvey P. Dale, Apr 13 2015 *)

Extensions

More terms from D. S. McNeil, Mar 23 2009