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 A089833 #9 May 18 2024 14:52:03 %S A089833 0,1,10,115,1666,30198,665148,17296851,518916970,17643220738, %T A089833 670442556004,28158587998814,1295295050441588,64764752531737100, %U A089833 3497296636751245560,202843204931717665155,12576278705767060962330 %N A089833 a(n) = A000108(n)*(A000142(n+1)-1). %F A089833 a(n) = A001813(n) - A000108(n). %o A089833 (MIT/GNU Scheme) (define (A089833 n) (* (A000108 n) (-1+ (A000142 (1+ n))))) %Y A089833 The first column of A089831. %Y A089833 Cf. A000108, A001813, A089835. %K A089833 nonn %O A089833 0,3 %A A089833 _Antti Karttunen_, Dec 05 2003