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 A096124 #3 Mar 31 2012 14:11:24 %S A096124 1,4,11,27,72 %N A096124 a(n) is the exponent of 5 in x = 2^m*5^n, where x = b(n)-b(n-1) and b(n) and b(n-1) are consecutive terms in A050649. %e A096124 a(3) = 4: b(3)-b(2) = 2512-12 = 2500; 2500 = 2^2*5^4, hence a(3)=4. %Y A096124 Cf. A050649. %K A096124 nonn %O A096124 2,2 %A A096124 _Ray G. Opao_, Jul 23 2004