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 A070840 #5 Dec 05 2013 19:55:19 %S A070840 0,1,2,11,3,111,4,22,1111,5,11111,6,33,222,111111,7,1111111,8,44,2222, %T A070840 11111111,9,333,111111111,55,22222,1111111111,11111111111,66,444,3333, %U A070840 222222,111111111111,1111111111111,77,2222222,11111111111111,555,33333 %N A070840 Repdigits (A010785) ordered by sum of digits (A007953). %C A070840 If n has no divisors among 2,3,5 or 7 then the only term with digit sum n is the repunit A002275(n) = 1111... n times. %Y A070840 Cf. A070841. %K A070840 base,nonn %O A070840 1,3 %A A070840 _Amarnath Murthy_, May 12 2002 %E A070840 Edited and extended by _Ray Chandler_, Feb 10 2009