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 A161751 #12 Jan 21 2022 23:31:03 %S A161751 1,2,3,4,5,7,9,2,4,6,8,1,5,7,2,4,6,8,1,5,7,9,2,4,6,8,5,7,2,4,6,8,1,5, %T A161751 7,2,4,6,8,1,5,7,9,2,4,8,1,5,7,2,4,6,1,5,7,2,4,6,8,1,5,7,9,4,6,8 %N A161751 Digital root of Abelian numbers (A051532). %C A161751 It is interesting to observe that it is difficult to find 3 as the digital root. %C A161751 This is because if a term of A051532 is congruent to 3 (mod 9) all other prime power divisors of the number must be 2 (mod 3). The first few indexes n with a(n) = 3 are 3, 99, 131, 164, 211, 261, 293, 327, 351, 424, 450, 482, 491, .... - _Charles R Greathouse IV_, Feb 13 2011 %e A161751 161 is an Abelian number whose digital root is 8. %Y A161751 Cf. A051532. %K A161751 nonn,base %O A161751 1,2 %A A161751 _Parthasarathy Nambi_, Jun 17 2009