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 A131446 #7 Jan 28 2025 08:38:08 %S A131446 1,1,1,8,15,720,5040,13440,13440,3628800,532224,43545600,691891200, %T A131446 691891200,108972864000,1902071808000,118562476032000,6847458508800, %U A131446 24329020081766400,17888985354240000,1344498478202880000 %N A131446 Denominators of n-th approximation of factorial (also called harmonic) expansion of Pi. %C A131446 Numerators are given in A131445. %C A131446 For the rationals r(n) and some values see the W. Lang link under A131445. %F A131446 a(n) = denominator(r(n)), with r(n):=sum(b(k)/k!,n=1..n) with b(k):=A075874(k) (factorial expansion of Pi). %e A131446 Rationals r(n): [3,3,3,25/8,47/15,2261/720,15833/5040,42223/13440,42223/13440,...]. %Y A131446 Cf. A000796, A131445. %K A131446 nonn,frac,easy %O A131446 1,4 %A A131446 _Wolfdieter Lang_, Aug 07 2007