A225792 Numbers n such that the sum of first n nontrivial prime powers (A025475 excluding 1) is divisible by n.

1, 2, 3, 9, 13, 54, 384, 596, 7289, 18136, 226871, 1577601, 5240465, 13389981, 130707763, 157598052, 617834651, 998713177, 4596574856

Offset: 1

Author

Alex Ratushnyak, May 16 2013

Keywords

• nonn
• more

Comments

a(16) > 146306912. There are 146306912 nontrivial prime powers <= 2^63. - Donovan Johnson, May 16 2013

a(20) > 41.2*10^9. - Giovanni Resta, May 16 2013

Examples

			The sum of first 9 nontrivial prime powers is 4 + 8 + 9 + 16 + 25 + 27 + 32 + 49 + 64 = 234. Because 234 is divisible by 9, the latter is in the sequence.
		

Crossrefs

Cf. A025475, A225791.

Extensions

a(12)-a(15) from Donovan Johnson, May 16 2013

a(16)-a(19) from Giovanni Resta, May 16 2013