A262194 Number of compositions of n such that the maximal distance between two identical parts equals two.

0, 0, 0, 1, 1, 4, 6, 13, 23, 42, 68, 119, 197, 324, 530, 823, 1305, 2040, 3162, 4869, 7431, 11076, 16680, 24831, 36785, 54210, 79546, 115967, 167359, 241726, 347184, 496235, 707681, 1004534, 1421178, 2003969, 2806921, 3929770, 5479406, 7617149, 10562169

Offset

0,6

Links

Table of n, a(n) for n=0..40.

Example

a(3) = 1: 111.
a(4) = 1: 121.
a(5) = 4: 131, 212, 1112, 2111.
a(6) = 6: 141, 222, 1113, 1212, 2121, 3111.
a(7) = 13: 151, 232, 313, 1114, 1213, 1222, 1312, 2131, 2221, 3121, 4111, 11122, 22111.
a(8) = 23: 161, 242, 323, 1115, 1214, 1232, 1313, 1412, 2123, 2141, 2321, 3131, 3212, 4121, 5111, 11123, 11132, 11222, 21113, 22211, 23111, 31112, 32111.

Crossrefs

Column k=2 of A262191.

Sequence in context: A284798 A120463 A049732 * A136391 A105205 A302311

Adjacent sequences: A262191 A262192 A262193 * A262195 A262196 A262197

Keyword

nonn

Author

Alois P. Heinz, Sep 14 2015

Status

approved