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 A124738 #10 Oct 11 2019 11:00:00
%S A124738 1,1,1,1,3,1,1,5,1,3,5,1,5,7,1,7,1,3,7,9,1,5,7,1,5,7,11,1,3,5,9,11,1,
%T A124738 11,13,1,7,11,13,1,3,5,7,9,11,13,15,1,5,7,11,13,1,5,7,11,13,17,1,3,7,
%U A124738 9,11,13,17,1,11,13,17,19,1,5,13,17,19,1,3,5,7,9,13,15,17,19,21,1,5,7,11,13
%N A124738 Irregular table where the n-th row consists of those positive integers which are coprime to both n and n+1 and which are <= n.
%C A124738 The n-th row has A057475(n) terms.
%e A124738 The positive integers which are coprime to 8 and which are <= 8 are 1,3,5,7. The integers which are coprime to 9 and which are <= 9 are 1, The integers in both these sequences (1,5,7) make up the row of A124738.
%t A124738 f[n_] := Select[Range[n], GCD[n, # ] == GCD[n + 1, # ] == 1 &]; Flatten[Table[f[n], {n, 23}]] (* _Ray Chandler_, Nov 10 2006 *)
%Y A124738 Cf. A057475, A124739, A124740, A124741.
%K A124738 nonn,tabf
%O A124738 1,5
%A A124738 _Leroy Quet_, Nov 06 2006
%E A124738 Extended by _Ray Chandler_, Nov 10 2006