A242837 Number of compositions of n with difference -4 between the number of odd parts and the number of even parts, both counted without multiplicity.
24, 0, 84, 0, 288, 0, 822, 0, 2226, 0, 5304, 720, 15034, 10680, 55624, 84360, 265200, 527640, 1342608, 2886960, 6673176, 14433240, 31725930, 67718568, 144265370, 302771208, 631156708, 1303769496, 2673673704, 5447789784, 11028089996, 22211684328, 44491303391
Offset: 20
Keywords
Examples
a(20) = 24 = 4!: all permutations of {2,4,6,8}.
Links
- Alois P. Heinz, Table of n, a(n) for n = 20..500
Crossrefs
Column k=-4 of A242626.
Comments