A158149 Number of nondecreasing integer sequences of length 15 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 225, 483, 892, 1726, 2999, 5517, 9136, 15691, 25423, 41668, 64943, 102972, 155880, 238808, 353814, 525710, 760658, 1106657, 1568464, 2228879, 3108245, 4333985, 5940271, 8151896, 11007043, 14867782, 19823198, 26397150

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..405

Formula

a(n) = A000041(n)^2 for n <= 7.

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

Crossrefs

Column k=15 of A389686.

Sequence in context: A158146 A158147 A158148 * A158150 A158151 A158152

Adjacent sequences: A158146 A158147 A158148 * A158150 A158151 A158152

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved