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 A014644 #20 Oct 22 2022 14:30:35
%S A014644 1,2,2,3,5,11,38,272,6474,1090483,4363282578,2940715000315189,
%T A014644 7930047000157075949085439,14412592242471457956514645440241289655074,
%U A014644 70636608026754077888330819116433040562582634705380432362008848092
%N A014644 Form array starting with {1,1}; then i-th term in a row gives number of i's in next row; sequence is formed from final term in each row.
%F A014644 log a(n) grows like a constant times phi^n, where phi = golden ratio. - _Colin Mallows_
%F A014644 a(n) converges to a(n-2)*a(n-1)*phi (within 6 decimals for a(15)). - _Johan Claes_, Oct 02 2005
%F A014644 Limit_{n -> oo} a(n+2)/(a(n+1)*a(n)) = 1/phi. - _Benoit Cloitre_, Oct 13 2005
%e A014644 a(5)=5 because 5 is the last number of the 5th row of A014643, (1,2,2,3,3,4,4,4,5,5,5).
%t A014644 NestList[Flatten@ MapIndexed[ConstantArray[First[#2], #1] &, #] &, {1, 1}, 8][[All, -1]] (* _Michael De Vlieger_, Dec 16 2021 *)
%Y A014644 Cf. A014643, A011784.
%K A014644 nonn,nice
%O A014644 1,2
%A A014644 _N. J. A. Sloane_
%E A014644 a(1)-a(11) computed by _Colin Mallows_
%E A014644 a(12)-a(15) computed by _Johan Claes_ Oct 02 2005