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 A387094 #10 Aug 23 2025 10:21:29 %S A387094 1,4,2,6,3,12,8,10,5,15,9,18,14,20,16,22,11,33,21,27,24,26,13,39,30, %T A387094 32,28,34,17,51,36,38,19,57,42,44,40,45,25,35,7,56,46,50,48,54,52,58, %U A387094 29,87,60,62,31,93,63,66,55,70,49,84,64,72,68,74,37,111,69 %N A387094 An infinite variant of the EKG sequence (A064413) such that for any n > 0, a(2*n) > a(2*n-1) and a(2*n) > a(2*n+1). %C A387094 For the sequence to be infinite, when computing a term with even index, say a(2*n) for some n > 1, we must ensure that some missing value v < a(2*n) such that gcd(a(2*n), v) != 1 exists. %C A387094 Will every integer appear in the sequence? %H A387094 Rémy Sigrist, <a href="/A387094/b387094.txt">Table of n, a(n) for n = 1..10001</a> %H A387094 Rémy Sigrist, <a href="/A387094/a387094.gp.txt">PARI program</a> %H A387094 <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a> %e A387094 Sequence begins: %e A387094 n a(n) %e A387094 -- ---- %e A387094 1 1 %e A387094 2 4 %e A387094 3 2 %e A387094 4 6 %e A387094 5 3 %e A387094 6 12 %e A387094 7 8 %e A387094 8 10 %e A387094 9 5 %e A387094 10 15 %e A387094 11 9 %e A387094 12 18 %e A387094 13 14 %e A387094 14 20 %e A387094 15 16 %e A387094 16 22 %e A387094 17 11 %o A387094 (PARI) \\ See Links section. %Y A387094 Cf. A064413. %K A387094 nonn,new %O A387094 1,2 %A A387094 _Rémy Sigrist_, Aug 16 2025