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 A114861 #13 Oct 11 2019 16:22:06
%S A114861 2,1,4,3,7,5,6,11,8,9,10,13,12,17,14,15,16,19,18,23,20,21,22,25,24,29,
%T A114861 26,27,28,31,30,37,32,33,34,35,36,41,38,39,40,43,42,47,44,45,46,49,48,
%U A114861 53,50,51,52,55,54,59,56,57,58,61,60,67,62,63,64,65,66,71,68,69,70,73
%N A114861 a(n) is smallest positive integer not among the earlier terms of the sequence, not equal to n and which is coprime to its adjacent terms in the sequence.
%C A114861 Sequence is a permutation of the positive integers. (Inverse permutation is sequence A114862.)
%e A114861 a(8) = 11 since 11 is the smallest positive integer not among the first 7 terms of the sequence, not equal to 8 and which is coprime to a(7) = 6.
%t A114861 f[l_] := Block[{k = 1}, While[k == Length[l] + 1 || MemberQ[l, k] || GCD[k, Last[l]] > 1, k++ ]; Return[Append[l, k]]; ]; Nest[f, {}, 76] (* _Ray Chandler_, Jan 02 2006 *)
%Y A114861 Cf. A114862.
%K A114861 nonn
%O A114861 1,1
%A A114861 _Leroy Quet_, Jan 02 2006
%E A114861 More terms from _Ray Chandler_ and _Klaus Brockhaus_, Jan 02 2006