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 A173575 #3 Aug 24 2012 10:50:03 %S A173575 1,2,3,4,5,6,39 %N A173575 5-Factorions: equal to the sum of the quintuple factorials of their digits in base 10. %e A173575 39 -> 3!!!!! + 9!!!!! = 3 + 9*4 = 3 + 36 = 39. %p A173575 P:=proc(n,m) local a,b,i,j,k,x,w; for i from 1 by 1 to n do a:=0; b:=0; w:=0; k:=i; while k>0 do w:=k-(trunc(k/10)*10); j:=w; x:=w-m; if w=0 then b:=1; else while x>0 do j:=j*x; x:=x-m; od; b:=j; fi; a:=a+b; k:=trunc(k/10); od; if a=i then lprint(i,a); fi; od; end: P(1000,5); %Y A173575 A014080, A097653, A173573, A173574, A173576, A173577 %K A173575 easy,fini,nonn,base %O A173575 1,2 %A A173575 _Paolo P. Lava_ and _Giorgio Balzarotti_, Feb 22 2010