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.
%I A351533 #10 Feb 13 2022 13:38:59 %S A351533 45,117,153,261,333,369,405,477,549,657,801,873,909,981,1017,1053, %T A351533 1233,1341,1377,1413,1557,1629,1737,1773,2061,2097,2169,2205,2313, %U A351533 2349,2421,2493,2529,2637,2817,2853,2925,2997,3033,3141,3177,3321,3357,3501,3573,3609,3645,3681,3789,3825,3897,4041,4113,4149,4293 %N A351533 Odd numbers k that are multiples of 3 and for which sigma(k) is congruent to 2 modulo 4. %H A351533 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %t A351533 Select[3*Range[1, 1400, 2], Mod[DivisorSigma[1, #], 4] == 2 &] (* _Amiram Eldar_, Feb 13 2022 *) %o A351533 (PARI) isA351533(n) = ((n%2) && !(n%3) && (2 == (sigma(n)%4))); %Y A351533 Intersection of A008585 and A191218. Complement of A351535 in A191218. %Y A351533 Cf. A351534 (subsequence). %K A351533 nonn %O A351533 1,1 %A A351533 _Antti Karttunen_, Feb 13 2022