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 A145427 #12 Jun 19 2023 06:41:00
%S A145427 0,2,9,9,0,1,1,0,0,2,7,2,3,3,9,6,5,4,7,0,8,6,2,2,7,4,9,9,6,9,0,3,7,7,
%T A145427 8,3,8,2,8,4,2,4,8,5,1,8,1,0,1,9,7,6,5,6,6,0,3,3,3,7,3,4,4,0,5,5,0,1,
%U A145427 1,2,0,5,6,0,4,8,0,1,3,1,0,7,5,0,4,4,3,3,5,0,9,2,9
%N A145427 Decimal expansion of Sum_{n>=0} (n!/(n+3)!)^2.
%D A145427 Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch, (1996), 4.1.32.
%F A145427 Equals A091476 - 2.4375.
%e A145427 0.0299011002723396547...
%p A145427 1/4*Pi^2-39/16 ;
%t A145427 RealDigits[Pi^2/4 - 39/16, 10, 120, -1][[1]] (* _Amiram Eldar_, Jun 19 2023 *)
%Y A145427 Cf. A091476, A145426.
%K A145427 cons,easy,nonn
%O A145427 0,2
%A A145427 _R. J. Mathar_, Feb 08 2009