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 A134623 #16 Sep 25 2024 01:52:23
%S A134623 2,3,5,7,8,9,11,12,13,15,17,19,20,21,23,25,28,29,30,31,32,33,35,36,37,
%T A134623 39,41,43,44,45,47,48,49,51,53,54,55,56,57,59,61,63,65,67,68,69,71,73,
%U A134623 76,77,78,79,80,81,83,84,85,87,89,91,92,93,95,97,100,101,102
%N A134623 a(n) = the n-th positive integer which is missing from A134624.
%C A134623 A134624(1) = 1. A134624(n) is the smallest integer which is > A134624(n-1) and is different from and not coprime to a(n-1). [corrected by _Michel Marcus_, Sep 06 2019]
%o A134623 (PARI) missing(n, v) = {my(nb = 0, k = 1, s = Set(v), ok = 0); while(!ok, if (! setsearch(s, k), nb++); ok = (nb == n); if (!ok, k++);); k;}
%o A134623 nextt(start, cop) = {my(k = max(start+1, cop+1)); while(gcd(k, cop) == 1, k++); k;}
%o A134623 list3(nn) = {my(v3 = vector(nn), v4 = vector(nn)); v4[1] = 1; for (n=1, nn, v3[n] = missing(n, v4); if (n+1 > nn, break); v4[n+1] = nextt(v4[n], v3[n]);); v3} \\ _Michel Marcus_, Sep 06 2019
%Y A134623 Cf. A053661, A134624.
%K A134623 nonn
%O A134623 1,1
%A A134623 _Leroy Quet_, Nov 04 2007
%E A134623 More terms from _Michel Marcus_, Sep 06 2019