A329310 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.

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

Offset

1,6

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, C program for A329310

Rémy Sigrist, Scatterplot of the first 500000 terms

Example

The first terms, alongside the corresponding k's, are:
  n    a(n)  k's
  ---  ----  ---------
    1     0  {}
    2     0  {}
    3     1  {1}
    4     0  {}
    5     0  {}
    6     3  {1, 2}
    7     3  {3}
    8     4  {1, 3}
    9     4  {4}
   10     1  {1}
   11     0  {}
   12     0  {}
   13     1  {1}
   14     0  {}
   15     0  {}
   16     6  {1, 2, 3}
   17    16  {3, 6, 7}

Prog

(C) See Links section.

Crossrefs

See A329257 for similar sequences.

Sequence in context: A343443 A351348 A246011 * A061023 A355954 A057690

Adjacent sequences: A329307 A329308 A329309 * A329311 A329312 A329313

Keyword

nonn

Author

Rémy Sigrist, Nov 10 2019

Status

approved