login
A171661
Triangle T(n,k) (n >= 0, 0 <= k <= n) read by rows: T(n,0) = T(n,1) = A000984(n); for n >= 2 and k >= 2, T(n,k) = T(n,k-1) - T(n-1,k-2).
1
1, 2, 2, 6, 6, 4, 20, 20, 14, 8, 70, 70, 50, 30, 16, 252, 252, 182, 112, 62, 32, 924, 924, 672, 420, 238, 126, 64, 3432, 3432, 2508, 1584, 912, 492, 254, 128, 12870, 12870, 9438, 6006, 3498, 1914, 1002, 510, 256, 48620, 48620, 35750, 22880, 13442, 7436
OFFSET
0,2
EXAMPLE
Triangle starts:
1
2,2
6,6,4
20,20,14,8
70,70,50,30,16
CROSSREFS
Sequence in context: A033712 A033730 A033754 * A276418 A173869 A247377
KEYWORD
nonn,tabl
AUTHOR
Mark Dols, Dec 14 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jan 24 2010
More terms from Mark Dols, Jan 24 2010
STATUS
approved