A232704 Numbers n such that sigma(n)+n divides sigma(n^2).

84889, 376443, 1260615, 2703555, 4883751, 7551847, 8894695, 9387081, 10142181, 12600825, 39450985, 57924711, 72978693, 73534503, 166503105, 428777995, 563715879, 578643967, 583540893, 1181555907, 1598569785, 1779455211, 2917138191, 3078534559, 3318534361

Offset: 1

Author

Alex Ratushnyak, Nov 28 2013

Keywords

• nonn

Crossrefs

Cf. A000203 (sigma(n) = sum of divisors of n).

Cf. A232547, A232703.

Programs

PARI

for(n=1, 10^8, if(sigma(n^2)%(sigma(n)+n)==0, print1(n ", "))) \\ Donovan Johnson, Nov 30 2013

Extensions

a(23)-a(25) from Donovan Johnson, Nov 30 2013