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 A114020 #4 Mar 03 2023 23:11:32 %S A114020 0,1,2,3,8,40326 %N A114020 a(n) = a(n-1)! + a(n-2)! with a(0) = 0, a(1) = 1. %C A114020 a(6) is too large to include. %C A114020 Essentially a duplicate of A005604. %e A114020 a(5) = a(4)! + a(3)! = 8! + 3! = 40320 + 6 = 40326. %Y A114020 Cf. A000045, A005604. %K A114020 nonn %O A114020 0,3 %A A114020 _Parthasarathy Nambi_, Jan 31 2006