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A262196
Number of compositions of n such that the maximal distance between two identical parts equals three.
1
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
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 14 2015
STATUS
approved