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 A216103 #6 Sep 02 2012 17:50:03 %S A216103 1,6,7,2,3,9,3,1,2,2,4,0,4,0,0,4,6,6,4,3,5,2,4,7,5,6,9,1,7,6,4,2,8,8, %T A216103 2,4,2,4,6,5,5,1,1,9,9,0,0,5,4,7,1,6,5,3,3,1,9,0,0,3,8,5,3,6,3,8,5,5, %U A216103 1,4,4,3,8,0,8,9,4,0,5,1,2,8,7,7,0,4,5,2,5,2,7,3,1,1,8,5 %N A216103 [3^(5*10^(n+1)) mod 10^(2n+3) - 1]/(10^(2n+2)) mod 10. %C A216103 3^500 ends in 7610001 %C A216103 3^5000 ends in 276100001 %C A216103 3^50000 ends in 32761000001 %C A216103 3^500000 ends in 9327610000001 %C A216103 The last digits before the zeros are converging to the present sequence. %Y A216103 Cf. A007185, A016090, A091663, A018248, A091664, A018247. %Y A216103 A216102 gives the 10's-complement. %K A216103 nonn,base %O A216103 1,2 %A A216103 _V. Raman_, Sep 01 2012