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 A152839 #16 Jun 03 2025 10:33:26 %S A152839 0,0,1,5,-96 %N A152839 a(0) = 0; a(n) = n! - a(n-1)!. %Y A152839 Cf. A084964, A152832, A152833, A152835, A152836, A152837, A152838 %K A152839 sign,fini,full,less %O A152839 0,4 %A A152839 _Vladimir Joseph Stephan Orlovsky_, Dec 14 2008 %E A152839 Indices added to definition, offset corrected - _R. J. Mathar_, Jan 08 2009 %E A152839 Definition corrected by _Georg Fischer_, Jun 03 2025