A357461 Odd numbers whose number of deficient divisors is equal to their number of nondeficient divisors.

3010132125, 4502334375, 5065535475, 6456074625, 8813660625, 9881746875, 15395254875, 15452011575, 16874983125, 18699305625, 19814169375, 19909992375, 21380506875, 25366375125, 26643400875, 26746594875, 28943578125, 31562182575, 33074966925, 34315506225, 35300640375

Offset

1,1

Comments

The odd terms of A357460.

If there are no odd perfect numbers, then this sequence is also the subsequence of the odd terms of A335543.

The first 100 terms are all divisible by 4725 = 3^3 * 5^2 * 7.

Links

Amiram Eldar, Table of n, a(n) for n = 1..100

Prog

(PARI) is(n) = n%2 && sumdiv(n, d, if(sigma(d, -1) < 2, 1, -1)) == 0;

Crossrefs

Subsequence of A005101, A005231 and A357460.

Cf. A335543.

Sequence in context: A204338 A185889 A186093 * A336966 A333127 A225140

Adjacent sequences: A357458 A357459 A357460 * A357462 A357463 A357464

Keyword

nonn

Author

Amiram Eldar, Sep 29 2022

Status

approved