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 A112586 #3 Mar 31 2012 10:30:58 %S A112586 1,3,15,50,171,69,461,78,12203,312,318880,2184,57725,5804,6698,5091 %N A112586 Lengths of the loop of the sequences "Sum of last n digits" beginning with (n-1) zeros followed by digit 7. %e A112586 a(4)=50 because the sum of last four *digits* of the sequence beginning with 0,0,0,7, (three zeros followed by a 7) enters in a loop whose length is 50 terms; so a(4)=50 %e A112586 a(5)=171 because "Sum of last five digits" beginning with 0,0,0,0,7 enters in a cycle of 171 terms. %e A112586 Computed by Michael D Beeler. %Y A112586 Cf. A112395. %K A112586 base,easy,nonn %O A112586 1,2 %A A112586 _Alexandre Wajnberg_, Dec 17 2005