A046347 Odd composite numbers divisible by the sum of their prime factors (counted with multiplicity).

27, 105, 231, 627, 805, 897, 945, 1581, 1755, 2079, 2625, 2967, 3055, 3125, 3861, 4185, 4543, 5355, 5445, 5487, 5967, 6075, 6461, 6525, 6745, 7881, 8085, 8505, 8883, 9555, 9717, 10125, 10647, 10707, 11375, 11385, 12675, 12789, 13005, 13275, 13475

Offset: 1

Author

Patrick De Geest, Jun 15 1998

Keywords

• nonn

Examples

			897 is a term since 897 = 3 * 13 * 23 and 3 + 13 + 23 = 39 and 897 / 39 = 23.
		

Links

• T. D. Noe, Table of n, a(n) for n=1..1000

Crossrefs

Cf. A001414, A046346, A046348.

Programs

Mathematica

Select[Range[9,13500,2],!PrimeQ[#]&&IntegerQ[#/Total[Times@@@FactorInteger[#]]]&] (* Jayanta Basu, Jun 04 2013 *)

PARI

sopfr(n) = {my(f=factor(n)); sum(k=1, #f~, f[k, 1]*f[k, 2]); } \\ A001414
lista(nn) = forcomposite(n=2, nn, if ((n%2) && !(n % sopfr(n)), print1(n, ", ")); ); \\ Michel Marcus, Feb 06 2019

Extensions

Name clarified by Michel Marcus, Feb 06 2019