A158181 - OEIS

A158181

Number of nondecreasing integer sequences of length 47 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, 2480624, 3833756, 5934058, 9059961, 13823090, 20838010, 31401684, 46805397, 69688456, 102842416

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OFFSET

1,2

COMMENTS

a(n) = A000041(n)^2 for n<=23

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: A158178 A158179 A158180 * A158182 A158183 A158184

Adjacent sequences: A158178 A158179 A158180 * A158182 A158183 A158184

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 13 2009

STATUS

approved