A158182 Number of nondecreasing integer sequences of length 48 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, 1575025, 2480625, 3833761, 5934078, 9060026, 13823275, 20838491, 31402849, 46808062, 69694278, 102854636

Offset

1,2

Comments

a(n) = A000041(n)^2 for n<=24

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

Links

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

Crossrefs

Sequence in context: A158179 A158180 A158181 * A158183 A158184 A001255

Adjacent sequences: A158179 A158180 A158181 * A158183 A158184 A158185

Keyword

nonn

Author

R. H. Hardin Mar 13 2009

Status

approved