cp's OEIS Frontend

A366474 Where n appears in A337136, or -1 if n never appears.

%I A366474 #13 Jun 21 2025 01:58:59
%S A366474 1,2,3,5,4,6,8,7,9,10,35,13,22,16,18,19,33,23,11,25,27,26,64,29,32,31,
%T A366474 34,36,12,37,20,38,40,39,44,42,45,46,43,47,14,48,28,49,51,50,21,53,52,
%U A366474 55,56,58,15,59,61,60,62,63,228,65,99,24,69,68,67,71,17,76
%N A366474 Where n appears in A337136, or -1 if n never appears.
%H A366474 Michael De Vlieger, <a href="/A366474/b366474.txt">Table of n, a(n) for n = 1..10000</a>
%t A366474 nn = 120; c[_] := 0; Array[Set[{a[#], c[#]}, {#, #}] &, 2]; Set[{i, j, u}, Range[3]]; s = i + j;
%t A366474 Do[k = u; While[Or[c[k] > 0, CoprimeQ[s, k]], k++];
%t A366474   Set[{a[n], c[k], i, j, s}, {k, n, j, k, j + k}];
%t A366474   If[k == u, While[c[u] > 0, u++]], {n, 3, nn}];
%t A366474 TakeWhile[Array[c, nn], # > 0 &] (* _Michael De Vlieger_, Oct 26 2023 *)
%Y A366474 Cf. A337136.
%K A366474 nonn
%O A366474 1,2
%A A366474 _N. J. A. Sloane_, Oct 26 2023