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
Keywords
Examples
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].
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..500
Crossrefs
Column k=1 of A242626.