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A387103 For any n >= 2, a(n) is the number of positive values k < A386482(n-1) missing from the first n-1 terms of A386482 such that gcd(k, A386482(n-1)) != 1.

%I A387103 #7 Aug 17 2025 09:54:38
%S A387103 0,0,0,1,0,0,2,2,0,1,0,2,2,0,2,1,0,0,5,3,3,1,1,0,1,0,2,2,0,1,0,6,10,8,
%T A387103 7,6,4,2,3,1,0,1,1,0,2,4,2,1,0,1,1,0,3,3,1,1,0,8,16,11,9,11,7,7,6,3,3,
%U A387103 2,1,0,1,1,0,0,1,0,17,31,22,20,28,24,16
%N A387103 For any n >= 2, a(n) is the number of positive values k < A386482(n-1) missing from the first n-1 terms of A386482 such that gcd(k, A386482(n-1)) != 1.
%C A387103 This sequence gives essentially the number of candidates for A386482(n) that are less than A386482(n-1).
%H A387103 Rémy Sigrist, <a href="/A387103/b387103.txt">Table of n, a(n) for n = 2..10000</a>
%H A387103 Rémy Sigrist, <a href="/A387103/a387103.png">Scatterplot of the candidates k for n = 2..1005</a>
%H A387103 Rémy Sigrist, <a href="/A387103/a387103.gp.txt">PARI program</a>
%F A387103 a(n) = 0 iff A386482(n) > A386482(n-1).
%e A387103 The first terms, alongside A386482(n) and the corresponding k's, are:
%e A387103   n   a(n)  A386482(n)  Candidates
%e A387103   --  ----  ----------  --------------------
%e A387103    1  N/A            1  N/A
%e A387103    2     0           2  {}
%e A387103    3     0           4  {}
%e A387103    4     0           6  {}
%e A387103    5     1           3  {3}
%e A387103    6     0           9  {}
%e A387103    7     0          12  {}
%e A387103    8     2          10  {8, 10}
%e A387103    9     2           8  {5, 8}
%e A387103   10     0          14  {}
%e A387103   11     1           7  {7}
%e A387103   12     0          21  {}
%e A387103   13     2          18  {15, 18}
%e A387103   14     2          16  {15, 16}
%e A387103   15     0          20  {}
%e A387103   16     2          15  {5, 15}
%e A387103   17     1           5  {5}
%e A387103   18     0          25  {}
%e A387103   19     0          30  {}
%e A387103   20     5          28  {22, 24, 26, 27, 28}
%o A387103 (PARI) \\ See Links section.
%Y A387103 Cf. A386482.
%K A387103 nonn
%O A387103 2,7
%A A387103 _Rémy Sigrist_, Aug 16 2025