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 A122025 #11 Oct 05 2019 09:57:24
%S A122025 1,1,1,1,1,2,5,13,29,109,629,4274,23329,170353,2034385,35152177,
%T A122025 494532481,7768108946,176258003381,7248370100941,266967020984381,
%U A122025 9997125891977197,431397731193035525,38079906742644329378
%N A122025 a(n) = (3*a(n-1)*a(n-4) - a(n-2)*a(n-3)) / a(n-5).
%t A122025 a[n_] := a[n] = (3*a[n - 1]a[n - 4] - a[n - 2]*a[n - 3])/a[n - 5]; a[0] = 1; a[1] = 1; a[2] = 1; a[3] = 1; a[4] = 1; Table[a[n], {n, 0, 30}]
%t A122025 RecurrenceTable[{a[1]==a[2]==a[3]==a[4]==a[5]==1,a[n]==(3a[n-1]a[n-4]-a[n-2]a[n-3])/a[n-5]},a,{n,30}] (* _Harvey P. Dale_, Sep 02 2017 *)
%Y A122025 Cf. A006722.
%K A122025 nonn
%O A122025 0,6
%A A122025 _Roger L. Bagula_, Sep 13 2006
%E A122025 Edited by _N. J. A. Sloane_, Sep 17 2006