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 A005921 M2871 #30 Jan 05 2025 19:51:33 %S A005921 1,3,10,48,312,2520,24480,277200,3588480,52254720,845510400, %T A005921 15048633600,292190976000,6146069529600,139223731046400, %U A005921 3379030566912000,87478184521728000,2406225451069440000,70080382582898688000 %N A005921 From solution to a difference equation. %D A005921 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005921 P. R. J. Asveld and N. J. A. Sloane, <a href="/A005442/a005442.pdf">Correspondence, 1987</a>. %H A005921 P. R. J. Asveld, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/25-4/asveld.pdf">Another family of Fibonacci-like sequences</a>, Fib. Quart., 25 (1987), 361-364. %F A005921 For n >= 1, a(n) = Fibonacci(n+3)*n!. - _David W. Wilson_, May 15 1997 %F A005921 For n >= 3, a(n) = n*(a(n-1)+a(n-2)*(n-1)). - _Christian Krause_, Dec 15 2024 %Y A005921 Cf. A000045, A000142. %K A005921 nonn,easy %O A005921 0,2 %A A005921 _N. J. A. Sloane_ %E A005921 More terms from _David W. Wilson_, May 15 1997