A158146 Number of nondecreasing integer sequences of length 12 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 222, 466, 828, 1537, 2546, 4506, 7097, 11656, 17964, 28080, 41533, 62829, 90245, 131868, 185633, 262931, 361620, 502438, 677292, 919091, 1221175, 1627409, 2126641, 2793158, 3599216, 4655834, 5933603, 7571871, 9539554

Offset

1,2

Comments

a(n) = A000041(n)^2 for n<=6

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..474

Crossrefs

Sequence in context: A030146 A229970 A038771 * A158147 A158148 A158149

Adjacent sequences: A158143 A158144 A158145 * A158147 A158148 A158149

Keyword

nonn

Author

R. H. Hardin Mar 13 2009

Status

approved