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 A088608 #6 May 22 2021 17:37:01
%S A088608 1,6,8,7,10,13,14,19,23,29,20,37,22,43,47,53,27,61,30,71,73,79,35,89,
%T A088608 97,101,103,107,44,113,46,131,137,139,149,151,54,163,167,173,58,181,
%U A088608 62,193,197,199,66,223,227,229,233,239,75,251,257,263,269,271,82,281,85,293
%N A088608 a(1) = 1, a(n) = prime(n) if n is composite else a(n) = composite(n).
%e A088608 a(9) = 23 = prime(9).
%t A088608 Join[{1},Module[{nn=100,cmps},cmps=Select[Range[2nn],CompositeQ];Table[ If[ PrimeQ[n],cmps[[n]],Prime[n]],{n,2,nn}]]] (* _Harvey P. Dale_, May 22 2021 *)
%Y A088608 Cf. A088607.
%K A088608 base,nonn
%O A088608 1,2
%A A088608 _Amarnath Murthy_, Oct 16 2003
%E A088608 More terms from _Ray Chandler_, Oct 18 2003