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 A112583 #3 Mar 31 2012 10:30:58 %S A112583 1,8,4,50,171,39,461,78,12203,312,318880,2184,57725,5804,1401,3251 %N A112583 Lengths of the loop of the sequences "Sum of last n digits" beginning with (n-1) zeros followed by digit 4. %e A112583 a(5)=171 because the sum of last five *digits* of the sequence beginning with 0,0,0,0,4, (four zeros followed by a 4) enters in a loop whose length is 171 terms; so a(5)=171 %e A112583 a(6)=39 because "Sum of last six digits" beginning with 0,0,0,0,0,4 enters in a cycle of 39 terms. %e A112583 Computed by Michael D Beeler. %Y A112583 Cf. A112395. %K A112583 base,easy,nonn %O A112583 1,2 %A A112583 _Alexandre Wajnberg_, Dec 17 2005