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

10,1

Links

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

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 *)

Crossrefs

Column k=5 of A242352.

Sequence in context: A367369 A033526 A078399 * A245658 A277664 A199836

Adjacent sequences: A243475 A243476 A243477 * A243479 A243480 A243481

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Jun 05 2014

Status

approved