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 A255825 #6 Mar 13 2015 18:47:42 %S A255825 1,2,3,4,1,1,1,1,1,2,1,2,1,2,3,1,2,3,1,4,2,3,1,4,1,2,3,1,4,1,1,2,3,1, %T A255825 1,4,1,1,2,1,3,1,1,4,1,1,1,2,1,2,3,1,1,4,1,1,1,1,2,2,1,2,3,1,1,1,4,1, %U A255825 1,2,1,1,2,2,3,1,2,3,1,1,1,1,4,1,2,1,2,1,1,3,2,2,3,1,1,2,3,1,1,4 %N A255825 A self-generating sequence: a(n) = n for n < 5; a(5n) = a(n); if every 5th term (a(5), a(10), a(15),...) is deleted, this gives back the original sequence. %C A255825 This is the m=5 analog of the m=10 variant A126616. Sequence A117943 is the m=3 analog with all terms decreased by 1. %F A255825 a(n) = a(n/5) if n==0 (mod 5); a(n) = a(n - floor(n/5)) otherwise. %o A255825 (PARI) a(n, m=5)=while(n>=m, if(n%m, n-=n\m, n\=m)); n \\ _M. F. Hasler_, Mar 07 2015 %Y A255825 Cf. A117943, A255824 - A255829, A126616. %K A255825 nonn %O A255825 1,2 %A A255825 _M. F. Hasler_, Mar 07 2015