A238871 Number of weakly unimodal compositions of n with absolute difference of successive parts <= 1.

1, 1, 2, 4, 6, 10, 14, 21, 27, 40, 52, 70, 92, 124, 156, 206, 264, 335, 425, 539, 673, 847, 1052, 1300, 1611, 1990, 2433, 2977, 3638, 4420, 5367, 6496, 7829, 9439, 11341, 13590, 16270, 19425, 23135, 27525, 32697, 38745, 45844, 54168, 63875, 75247, 88493, 103892

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Example

The a(8) = 27 such compositions are:
01:  [ 1 1 1 1 1 1 1 1 ]
02:  [ 1 1 1 1 1 1 2 ]
03:  [ 1 1 1 1 1 2 1 ]
04:  [ 1 1 1 1 2 1 1 ]
05:  [ 1 1 1 1 2 2 ]
06:  [ 1 1 1 2 1 1 1 ]
07:  [ 1 1 1 2 2 1 ]
08:  [ 1 1 1 2 3 ]
09:  [ 1 1 2 1 1 1 1 ]
10:  [ 1 1 2 2 1 1 ]
11:  [ 1 1 2 2 2 ]
12:  [ 1 2 1 1 1 1 1 ]
13:  [ 1 2 2 1 1 1 ]
14:  [ 1 2 2 2 1 ]
15:  [ 1 2 2 3 ]
16:  [ 1 2 3 2 ]
17:  [ 2 1 1 1 1 1 1 ]
18:  [ 2 2 1 1 1 1 ]
19:  [ 2 2 2 1 1 ]
20:  [ 2 2 2 2 ]
21:  [ 2 3 2 1 ]
22:  [ 2 3 3 ]
23:  [ 3 2 1 1 1 ]
24:  [ 3 2 2 1 ]
25:  [ 3 3 2 ]
26:  [ 4 4 ]
27:  [ 8 ]

Crossrefs

Cf. A001522, A001523, A005169, A034297, A238870, A238872.

Sequence in context: A103259 A280131 A082380 * A323595 A136460 A000065

Adjacent sequences: A238868 A238869 A238870 * A238872 A238873 A238874

Keyword

nonn

Author

Joerg Arndt, Mar 21 2014

Status

approved