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 A126022 #11 Mar 05 2024 16:32:24
%S A126022 1,2,4,7,10,13,17,21,25,30,35,40,46,52,58,64,71,78,85,92,100,108,116,
%T A126022 124,133,142,151,160,169,179,189,199,209,219,230,241,252,263,274,286,
%U A126022 298,310,322,334,346,359,372,385,398,411,424,438,452,466,480,494,508
%N A126022 a(1)=1; for n>1, a(n) = a(n-1) + (the number of terms of {a(k)} which are <= n).
%e A126022 There are four terms (1,2,4,7) of the sequence which are <= 9. So a(9) = a(8) + 4 = 25.
%t A126022 f[l_] := Block[{s = Length@l + 2}, Append[l, Last@l + Length@Select[l, # < s &]]]; Nest[f, {1}, 56] (* _Robert G. Wilson v_, Mar 01 2007 *)
%K A126022 easy,nonn
%O A126022 1,2
%A A126022 _Leroy Quet_, Feb 27 2007
%E A126022 More terms from _Robert G. Wilson v_, Mar 01 2007