A242841 Number of compositions of n with difference 1 between the number of odd parts and the number of even parts, both counted without multiplicity.

1, 1, 2, 1, 2, 8, 14, 45, 99, 230, 451, 953, 1798, 3503, 6683, 12693, 24209, 46155, 89200, 172767, 338255, 664453, 1317945, 2620363, 5243700, 10509348, 21141700, 42578221, 85897588, 173380086, 350184780, 707320136, 1428681390, 2885015407, 5823971576

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..500

Example

a(1) = 1: [1].
a(2) = 1: [1,1].
a(3) = 2: [1,1,1], [3].
a(4) = 1: [1,1,1,1].
a(5) = 2: [1,1,1,1,1], [5].
a(6) = 8: [1,1,1,1,1,1], [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1], [3,3].
a(7) = 14: [1,1,1,1,1,1,1], [1,1,2,3], [1,1,3,2], [1,2,1,3], [1,2,3,1], [1,3,1,2], [1,3,2,1], [2,1,1,3], [2,1,3,1], [2,3,1,1], [3,1,1,2], [3,1,2,1], [3,2,1,1], [7].

Crossrefs

Column k=1 of A242626.

Sequence in context: A219109 A137305 A282885 * A143208 A353581 A188664

Adjacent sequences: A242838 A242839 A242840 * A242842 A242843 A242844

Keyword

nonn

Author

Alois P. Heinz, May 23 2014

Status

approved