A158162 Number of nondecreasing integer sequences of length 28 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 225, 484, 900, 1764, 3136, 5929, 10201, 18225, 30973, 53343, 88135, 147976, 239366, 391166, 622410, 992731, 1550288, 2428726, 3729389, 5730799, 8676276, 13115757, 19565503, 29154058, 42913922, 63050667, 91706269

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..249

Formula

a(n) = A000041(n)^2 for n <= 14.

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

Crossrefs

Sequence in context: A158159 A158160 A158161 * A158163 A158164 A158165

Adjacent sequences: A158159 A158160 A158161 * A158163 A158164 A158165

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved