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 A156981 #5 Oct 15 2013 04:04:21 %S A156981 0,1,2,3,4,5,6,8,14,19,22,29,44,77,94,264,1414,5477 %N A156981 Numbers n with property that n^2 and (n+1)^2 have no common digits. %C A156981 Sequence is full, cf. A068802. %F A156981 a(n) = sqrt(A068802(n)). %o A156981 (PARI) isok(n) = length(setintersect(Set(digits(n^2)), Set(digits((n+1)^2)))) == 0; \\ _Michel Marcus_, Oct 15 2013 %Y A156981 Cf. A068802. %K A156981 fini,full,nonn,base %O A156981 1,3 %A A156981 _Zak Seidov_, Feb 20 2009