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 A292626 #35 Sep 01 2025 12:22:55 %S A292626 860,5336,6536,9656,16256,55796,70864,98048,361556,776096,2227616, %T A292626 4145216,4498136,4632896,8124416,13086016,34869056,38546576,150094976, %U A292626 172960856,196066256,962085536,1080008576,1733780336,1844788112,2143256576,2531343872,2986104064,9677743616,11276687456,17104503968,20680182272,21568135616 %N A292626 Numbers k whose abundance is 128: sigma(k) - 2*k = 128. %H A292626 Max Alekseyev, <a href="/A292626/b292626.txt">Table of n, a(n) for n = 1..87</a> %t A292626 fQ[n_] := DivisorSigma[1, n] == 2 n + 128; Select[ Range@ 10^8, fQ] (* _Robert G. Wilson v_, Nov 19 2017 *) %o A292626 (PARI) isok(n) = sigma(n) - 2*n == 128; \\ _Michel Marcus_, Sep 20 2017 %Y A292626 Subsequence of A259174. %Y A292626 Deficiency k: A191363 (k=2), A125246 (k=4), A141548 (k=6), A125247 (k=8), A101223 (k=10), A141549 (k=12), A141550 (k=14), A125248 (k=16), A223608 (k=18), A223607 (k=20), A223606 (k=22), A385255(k=24), A275702 (k=26), A387352 (k=32), A275997 (k=64). %Y A292626 Abundance k: A088831 (k=2), A088832 (k=4), A087167 (k=6), A088833 (k=8), A223609 (k=10), A141545 (k=12), A141546 (k=14), A141547 (k=16), A223610 (k=18), A223611 (k=20), A223612 (k=22), A223613 (k=24), A275701 (k=26), A175989 (k=32), A275996 (k=64). %K A292626 nonn,changed %O A292626 1,1 %A A292626 _Fabian Schneider_, Sep 20 2017 %E A292626 a(9)-a(18) from _Michel Marcus_, Sep 20 2017 %E A292626 a(19)-a(24), a(26), a(29)-a(30), a(33) from _Robert G. Wilson v_, Nov 20 2017 %E A292626 Missing terms a(25), a(27)-a(28), a(31)-a(32) inserted and terms a(34) onward added by _Max Alekseyev_, Aug 30 2025