A158179 Number of nondecreasing integer sequences of length 45 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, 1575024, 2480617, 3833726, 5933957, 9059666, 13822309, 20836093, 31397249, 46795621, 69667778, 102800226, 151372383, 221179471

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

Column k=45 of A389686.

Sequence in context: A158176 A158177 A158178 * A158180 A158181 A158182

Adjacent sequences: A158176 A158177 A158178 * A158180 A158181 A158182

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved