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.

A332459 Odd part of 1+sigma(n).

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%I A332459 #8 Feb 16 2020 17:36:30
%S A332459 1,1,5,1,7,13,9,1,7,19,13,29,15,25,25,1,19,5,21,43,33,37,25,61,1,43,
%T A332459 41,57,31,73,33,1,49,55,49,23,39,61,57,91,43,97,45,85,79,73,49,125,29,
%U A332459 47,73,99,55,121,73,121,81,91,61,169,63,97,105,1,85,145,69,127,97,145,73,49,75,115,125,141,97,169,81,187,61,127
%N A332459 Odd part of 1+sigma(n).
%H A332459 Antti Karttunen, <a href="/A332459/b332459.txt">Table of n, a(n) for n = 1..16384</a>
%H A332459 Antti Karttunen, <a href="/A332459/a332459.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%H A332459 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A332459 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A332459 a(n) = A000265(A088580(n)) = A000265(1+sigma(n)).
%F A332459 A002487(a(n)) = A324294(n).
%F A332459 a(2^n) = 0 for all n >= 0. [Zero occurs at least also at a(25). See A202274]
%o A332459 (PARI) A332459(n) = { my(s=1+sigma(n)); (s>>valuation(s,2)); };
%Y A332459 Cf. A000203, A000265, A002487, A088580, A161942, A202274, A324294, A332454, A332455.
%K A332459 nonn
%O A332459 1,3
%A A332459 _Antti Karttunen_, Feb 16 2020