A243478 Number of isoscent sequences of length n with exactly five descents.

22, 1546, 46947, 944701, 14745521, 193273378, 2228848403, 23305050081, 225560761204, 2051114040040, 17719591217257, 146674616051322, 1171101886353096, 9067551569835697, 68378670584901547, 504001041740002317, 3641720452674969516, 25859746275607624792

Offset: 10

Author

Joerg Arndt and Alois P. Heinz, Jun 05 2014

Keywords

• nonn

Links

• Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 10..100

Crossrefs

Column k=5 of A242352.

Programs

Mathematica

b[n_, i_, t_] := b[n, i, t] = If[n < 1, 1, Expand[Sum[ If[j < i, x, 1] *b[n - 1, j, t + If[j == i, 1, 0]], {j, 0, t + 1}]]]; a[n_] := Coefficient[b[n - 1, 0, 0], x, 5]; Table[a[n], {n, 10, 40}] (* Jean-François Alcover, Feb 09 2015, after A242352 *)