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 A192253 #9 Jul 12 2022 20:59:16 %S A192253 0,1,3,15,87,687,6447,71967,918687,13256607,212840607,3765435807, %T A192253 72741666207,1523637512607,34389853295007,832071217775007, %U A192253 21482864837231007,589515687506543007,17133249343107695007,525731414152434287007,16984313499467403887007 %N A192253 1-sequence of reduction of (n!) by x^2 -> x+1. %C A192253 See A192232 for definition of "k-sequence of reduction of [sequence] by [substitution]". After the tenth term, the final digit is 7, for terms in both A192253 and A192252. After the 100th term, the final 6 digits of terms in A192253 are 5,6,7,0,0,7. %F A192253 Conjecture: a(n) -n*a(n-1) -(n-1)*(n-3)*a(n-2) +(n-1)*(n-2)*a(n-3)=0. - _R. J. Mathar_, May 04 2014 %F A192253 Conjecture: partial sums of A005443. - _Sean A. Irvine_, Jul 12 2022 %t A192253 (See A192252.) %Y A192253 Cf. A192252, A192232. %K A192253 nonn %O A192253 1,3 %A A192253 _Clark Kimberling_, Jun 27 2011