A329310 - OEIS

%I #12 Nov 14 2019 12:52:38

%S 0,0,1,0,0,3,3,4,4,1,0,0,1,0,0,6,16,10,11,17,10,10,31,13,10,27,13,16,

%T 18,3,0,7,0,0,3,0,3,2,16,5,5,1,0,7,0,0,19,17,3,37,38,28,52,74,34,55,

%U 82,61,27,53,132,29,71,90,32,32,95,82,0,34,92,29,0,63

%N a(n) is the sum of the numbers k such that a(n-2*k) = a(n-k) and 0 < n-2*k < n-k < n.

%H Rémy Sigrist, <a href="/A329310/b329310.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A329310/a329310.txt">C program for A329310</a>

%H Rémy Sigrist, <a href="/A329310/a329310.png">Scatterplot of the first 500000 terms</a>

%e The first terms, alongside the corresponding k's, are:

%e   n    a(n)  k's

%e   ---  ----  ---------

%e     1     0  {}

%e     2     0  {}

%e     3     1  {1}

%e     4     0  {}

%e     5     0  {}

%e     6     3  {1, 2}

%e     7     3  {3}

%e     8     4  {1, 3}

%e     9     4  {4}

%e    10     1  {1}

%e    11     0  {}

%e    12     0  {}

%e    13     1  {1}

%e    14     0  {}

%e    15     0  {}

%e    16     6  {1, 2, 3}

%e    17    16  {3, 6, 7}

%o (C) See Links section.

%Y See A329257 for similar sequences.

%K nonn

%O 1,6

%A _Rémy Sigrist_, Nov 10 2019