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.

A332227 Odd numbers k such that sigma(k) is congruent to 2 modulo 8.

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%I A332227 #12 Jul 02 2021 01:54:33
%S A332227 17,41,73,89,97,113,137,153,193,233,241,257,281,313,325,337,353,369,
%T A332227 401,409,433,449,457,521,569,577,593,601,617,641,657,673,725,761,769,
%U A332227 801,809,833,845,857,873,881,925,929,937,953,977,1009,1017,1033,1049,1097,1129,1153,1193,1201,1217,1233,1249,1289,1297,1321
%N A332227 Odd numbers k such that sigma(k) is congruent to 2 modulo 8.
%H A332227 Antti Karttunen, <a href="/A332227/b332227.txt">Table of n, a(n) for n = 1..25000</a>
%H A332227 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%t A332227 Select[Range[1,1401,2],Mod[DivisorSigma[1,#],8]==2&] (* _Harvey P. Dale_, Apr 12 2021 *)
%o A332227 (PARI) isA332227(n) = ((n%2)&&2==(sigma(n)%8));
%Y A332227 Cf. A000203.
%Y A332227 Subsequence of A191218 and of A332226.
%Y A332227 Cf. A332228 (a subsequence, terms that are not prime powers).
%K A332227 nonn
%O A332227 1,1
%A A332227 _Antti Karttunen_, Feb 13 2020