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 A139378 #2 Mar 31 2012 10:32:17 %S A139378 1,1,3,1,1,3,1,1,9 %N A139378 Number of 2-digit multiples of n whose digits sum to n. %e A139378 a(1)=1 as 10 is the only 2-digit multiple of 1 whose digits sum to 1, while a(3)=3 as the multiples 12, 21 and 30 have the property. %K A139378 base,full,nonn,fini %O A139378 1,3 %A A139378 _Ian Duff_, Jun 08 2008