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 A322425 #12 Mar 15 2019 18:55:21
%S A322425 1,2,3,4,5,1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4,5,1,2,3,4,
%T A322425 1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,1,2,3,4,5,1,2,3,4,1,2,3,4,1,2,3,4,1,2,
%U A322425 3,4,1,2,3,1,2,3,4,5,1,2,3,4,1,2,3,4,1
%N A322425 Start with (1, 2, 3, 4, 5); if the sequence has n terms, extend it by appending a(n) copies of a(1..n-1): cf. "Look to the left" sequence A293630.
%H A322425 Iain Fox, <a href="/A322425/b322425.txt">Table of n, a(n) for n = 1..10000</a>
%F A322425 Lim_{n->infinity} (a(1) + a(2) + ... + a(n))/n = 2.55182072...
%t A322425 Nest[Join[#, Flatten@ ConstantArray[Drop[#, -1], #[[-1]]] ] &, Range@ 5, 2] (* _Michael De Vlieger_, Dec 08 2018 *)
%o A322425 (PARI) gen(n, v=[1, 2, 3, 4, 5], w) = for(x=1, n, w=vector(#v-1, i, v[i]); for(y=1, v[#v], v=concat(v, w))); v
%Y A322425 "Look to the left" sequences: A293630 (seed 1,2), A322423 (seed 1,2,3), A322424 (seed 1,2,3,4).
%Y A322425 Cf. A322426.
%K A322425 nonn
%O A322425 1,2
%A A322425 _Iain Fox_, Dec 07 2018
%E A322425 Self-contained definition from _M. F. Hasler_, Dec 10 2018