cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

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%I A357461 #10 Sep 30 2022 04:25:18
%S A357461 3010132125,4502334375,5065535475,6456074625,8813660625,9881746875,
%T A357461 15395254875,15452011575,16874983125,18699305625,19814169375,
%U A357461 19909992375,21380506875,25366375125,26643400875,26746594875,28943578125,31562182575,33074966925,34315506225,35300640375
%N A357461 Odd numbers whose number of deficient divisors is equal to their number of nondeficient divisors.
%C A357461 The odd terms of A357460.
%C A357461 If there are no odd perfect numbers, then this sequence is also the subsequence of the odd terms of A335543.
%C A357461 The first 100 terms are all divisible by 4725 = 3^3 * 5^2 * 7.
%H A357461 Amiram Eldar, <a href="/A357461/b357461.txt">Table of n, a(n) for n = 1..100</a>
%o A357461 (PARI) is(n) = n%2 && sumdiv(n, d, if(sigma(d, -1) < 2, 1, -1)) == 0;
%Y A357461 Subsequence of A005101, A005231 and A357460.
%Y A357461 Cf. A335543.
%K A357461 nonn
%O A357461 1,1
%A A357461 _Amiram Eldar_, Sep 29 2022