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 A245028 #25 Sep 08 2022 08:46:08 %S A245028 1,2,3,4,5,6,7,8,9,10,12,13,14,15,16,18,19,20,21,24,26,28,30,35,36,37, %T A245028 38,39,40,42,45,48,52,56,57,60,61,63,65,70,72,74,76,78,80,84,90,91,95, %U A245028 104,105,111,112,114,117,120,122,126,130,133,140,144,148,152 %N A245028 Divisors of 11^12 - 1. %C A245028 See Comments section in A245027. %C A245028 The following 36 triangular numbers belong to this sequence: 1, 3, 6, 10, 15, 21, 28, 36, 45, 78, 91, 105, 120, 171, 190, 210, 630, 666, 703, 741, 780, 1596, 1830, 4095, 4560, 5460, 6216, 16653, 33670, 46360, 103740, 115440, 221445, 274170, 365085, 392303547090. %C A245028 The following terms of A001082 (without 1, 21 and 120, which appear in the previous list) are in sequence: 5, 8, 16, 40, 56, 65, 133, 208, 280, 456, 481, 560, 936, 1008, 1281, 1365, 1680, 1776, 1976, 4880, 5985, 10920, 11285, 44408, 47880, 590520, 658008, 731120, 973560, 1046142792240. %C A245028 Also, 4/5 of the members are divisible by 3 and 2/3 of them are even. %H A245028 Bruno Berselli, <a href="/A245028/b245028.txt">Table of n, a(n) for n = 1..1920</a> %H A245028 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a> %e A245028 3138428376720 = 2^4 * 3^2 * 5 * 7 * 13 * 19 * 37 * 61 * 1117. %t A245028 Divisors[11^12 - 1] %o A245028 (PARI) divisors(11^12-1) %o A245028 (Sage) divisors(11^12-1) %o A245028 (Magma) Divisors(11^12-1); %o A245028 (Maxima) divisors(11^12-1); %Y A245028 Cf. Divisors of k^12-1: A003524 (k=2); A003532 (k=4); A245027 (k=7), A003543 (k=8), A027902 (k=9), A027897 (k=10). %K A245028 nonn,fini,full %O A245028 1,2 %A A245028 _Bruno Berselli_, Jul 10 2014