login
A158146
Number of nondecreasing integer sequences of length 12 with sum zero and sum of absolute values 2n.
1
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
CROSSREFS
Sequence in context: A030146 A229970 A038771 * A158147 A158148 A158149
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 13 2009
STATUS
approved