A158153 Number of nondecreasing integer sequences of length 19 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 225, 484, 900, 1763, 3128, 5891, 10062, 17795, 29809, 50475, 81654, 134082, 211205, 335898, 518266, 801010, 1208345, 1828868, 2704223, 4001769, 5820875, 8453498, 12088586, 17274220, 24332417, 34225314, 47579728

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..344

Formula

a(n) = A000041(n)^2 for n <= 9.

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

Crossrefs

Column k=19 of A389686.

Sequence in context: A158150 A158151 A158152 * A158154 A158155 A158156

Adjacent sequences: A158150 A158151 A158152 * A158154 A158155 A158156

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved