A241722 Number of compositions of n into distinct parts with exactly three descents.
1, 1, 2, 3, 5, 32, 35, 63, 93, 148, 205, 589, 674, 1111, 1551, 2344, 3140, 4616, 8210, 10370, 14976, 20564, 28598, 38244, 52451, 68597, 105527, 131194, 180087, 234267, 316204, 404032, 538282, 683281, 893039, 1205430, 1516912, 1949691, 2506797, 3192751, 4039430
Offset: 10
Keywords
Examples
a(14) = 5: [5,4,3,2], [8,3,2,1], [6,5,2,1], [7,4,2,1], [6,4,3,1]. a(15) = 32: [7,5,2,1], [9,3,2,1], [6,5,3,1], [7,4,3,1], [8,4,2,1], [6,4,3,2], [4,3,2,5,1], [3,5,4,2,1], [4,3,5,2,1], [5,2,4,3,1], [2,5,4,3,1], [4,2,5,3,1], [5,4,3,1,2], [5,1,4,3,2], [3,1,5,4,2], [5,3,1,4,2], [4,1,5,3,2], [1,5,4,3,2], [5,4,1,3,2], [4,3,1,5,2], [5,4,2,1,3], [2,1,5,4,3], [5,2,1,4,3], [4,2,1,5,3], [3,2,1,5,4], [5,3,2,1,4], [4,3,2,1,5], [5,4,2,3,1], [5,3,4,2,1], [4,5,3,2,1], [3,2,5,4,1], [5,3,2,4,1].
Links
- Alois P. Heinz, Table of n, a(n) for n = 10..1000
Crossrefs
Column k=3 of A241719.