A116660 Integers in both sequences A075658 and A067028.

56, 60, 84, 90, 104, 126, 132, 135, 140, 150, 152, 156, 184, 189, 196, 198, 204, 220, 224, 225, 228, 234, 240, 248, 260, 276, 294, 296, 297, 306, 308, 315, 330, 336, 340, 342, 344, 348, 350, 351, 360, 364, 372, 375, 376, 380, 414, 416, 424, 441, 444, 459

Offset

1,1

Comments

It could be argued that 1 should also be included in the sequence, if 0 is considered to be a composite, since the number of prime divisors (counted with multiplicity) of 1 and the sum of 1's distinct prime divisors are both 0.

Links

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

Example

60 = 2^2 *3^1 *5^1. Both the number of prime divisors (counted with multiplicity), 2+1+1 = 4 and the sum of the distinct prime divisors, 2+3+5 = 10, are composite. So 60 is in the sequence.

Mathematica

Select[Range[460], CompositeQ[Plus @@ (f = FactorInteger[#])[[;; , 1]]] && CompositeQ[Plus @@ f[[;; , 2]]] &] (* Amiram Eldar, Nov 14 2019 *)

Crossrefs

Cf. A075658, A067028, A116661.

Sequence in context: A345494 A345495 A045001 * A047727 A069810 A292896

Adjacent sequences: A116657 A116658 A116659 * A116661 A116662 A116663

Keyword

nonn

Author

Leroy Quet, Feb 21 2006

Extensions

More terms from R. J. Mathar, Aug 31 2007

Status

approved