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 A072862 #11 May 19 2020 09:12:53 %S A072862 1,4,9,16,25,36,64,81,100,121,144,225,256,289,324,400,484,529,576,625, %T A072862 729,841,900,1024,1089,1156,1296,1600,1681,1936,2025,2116,2209,2304, %U A072862 2401,2500,2601,2809,2916,3025,3364,3481,3600,4096,4356,4624,4761,5041 %N A072862 The smallest k>1 such that k divides sigma(k*n) is equal to 6. %C A072862 The smallest k>1 such that k divides sigma(k*n) is always 2, 3 or 6. Sequence generates squares but not all the squares (49, 169, 196, 361, 441, 676, 784, ... are the first squares not in the sequence). %C A072862 This is not the sequence of solutions to sigma(n) == 1 (mod 6), because 2401 is in this sequence but sigma(2401) == 5 (mod 6). See A074384 for more examples. - _R. J. Mathar_, May 19 2020 %F A072862 {n: A049605(n) = 6}. - _R. J. Mathar_, May 19 2020 %K A072862 easy,nonn %O A072862 1,2 %A A072862 _Benoit Cloitre_, Jul 26 2002