A262196 Number of compositions of n such that the maximal distance between two identical parts equals three.

0, 1, 2, 6, 12, 25, 46, 88, 152, 267, 452, 764, 1260, 2049, 3314, 5272, 8354, 13077, 20366, 31302, 48048, 72849, 110244, 165354, 247194, 366703, 541802, 796066, 1164264, 1695201, 2457904, 3549244, 5104908, 7313739, 10437170, 14848936, 21041422, 29732907

Offset

3,3

Links

Table of n, a(n) for n=3..40.

Example

a(4) = 1: 1111.
a(5) = 2: 1121, 1211.
a(6) = 6: 1131, 1221, 1311, 2112, 11112, 21111.
a(7) = 12: 1141, 1231, 1321, 1411, 2122, 2212, 11113, 11212, 12112, 21121, 21211, 31111.
a(8) = 25: 1151, 1241, 1331, 1421, 1511, 2132, 2222, 2312, 3113, 11114, 11213, 11312, 12113, 12122, 12212, 13112, 21131, 21221, 21311, 22121, 31121, 31211, 41111, 111122, 221111.

Crossrefs

Column k=3 of A262191.

Sequence in context: A210633 A304710 A137829 * A261667 A116562 A045925

Adjacent sequences: A262193 A262194 A262195 * A262197 A262198 A262199

Keyword

nonn

Author

Alois P. Heinz, Sep 14 2015

Status

approved