A158178 Number of nondecreasing integer sequences of length 44 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, 240100, 393129, 627264, 1004004, 1575022, 2480607, 3833690, 5933847, 9059366, 13821557, 20834323, 31393293, 46787161, 69650348, 102765500

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..199

Formula

a(n) = A000041(n)^2 for n <= 22.

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

Crossrefs

Sequence in context: A158175 A158176 A158177 * A158179 A158180 A158181

Adjacent sequences: A158175 A158176 A158177 * A158179 A158180 A158181

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved