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 A090626 #4 Mar 30 2012 18:50:43 %S A090626 1,0,1,0,0,1,0,1,0,1,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0, %T A090626 0,1,0,0,0,0,1,0,0,0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,0,1,0,1,0,0, %U A090626 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0 %N A090626 T(n,k) = if (k-th digit of pi) = (n-th digit of pi) then 1 else 0, 1<=k<=n (pi=3.14159... ), triangular array read by rows. %C A090626 A064823(n) = Sum(T(n,k): 1<=k<=n). %F A090626 T(n, k) = 0^((A000796(n) - A000796(k))^2). %K A090626 nonn,base,tabl %O A090626 1,1 %A A090626 _Reinhard Zumkeller_, Dec 12 2003