A158170 Number of nondecreasing integer sequences of length 36 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 225, 484, 900, 1764, 3136, 5929, 10201, 18225, 30976, 53361, 88209, 148225, 240097, 393111, 627190, 1003755, 1574291, 2478658, 3828864, 5922595, 9034439, 13768661, 20726392, 31180319, 46379938, 68892096, 101388705

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..222

Formula

a(n) = A000041(n)^2 for n <= 18.

a(n) = A000041(n)^2 - cumulative A000712(2*n-1-length), 0 <= 2*n-1-length <= floor(n/2) [empirical].

Crossrefs

Cf. A000041, A000712.

Sequence in context: A158167 A158168 A158169 * A158171 A158172 A158173

Adjacent sequences: A158167 A158168 A158169 * A158171 A158172 A158173

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved