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 A179655 #9 Jul 14 2015 01:10:50 %S A179655 3,9,2,6,3,9,4,6,3,9,2,6,3,7,9,6,8,3,7,9,6,1,3,5,9,4,6,3,9,6,3,5,9,6, %T A179655 3,7,9,6,3,5,9,6,3,7,9,2,6,1,3,9,4,6,8,3,9,6,3,9,6,8,3,9,2,6,1,3,9,6, %U A179655 3,7,9,2,6,3,5,9,6,3,7,9,6,8,1,3,9,4,6,8,3,9,2,6,3,5,9,4,6,3,9,2,6,3,9,6,8 %N A179655 Digital root of n-th abundant number. %e A179655 The 11th abundant number is 56. 5+6=11. 1+1=2. The digital root is 2. %t A179655 abQ[n_] := DivisorSigma[1, n] > 2 n; Mod[ Select[ Range@ 500, abQ], 9] /. 0 -> 9 (* _Robert G. Wilson v_, Aug 23 2010 *) %Y A179655 Cf. A005101. %K A179655 nonn,base %O A179655 1,1 %A A179655 _Jason G. Wurtzel_, Jul 22 2010 %E A179655 More terms from _Robert G. Wilson v_, Aug 23 2010