A158184 Number of nondecreasing integer sequences of length 50 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, 3833764, 5934093, 9060082, 13823450, 20838976, 31404082, 46810997, 69700899, 102868926

Offset: 1

Author

R. H. Hardin Mar 13 2009

Keywords

• nonn

Comments

a(n) = A000041(n)^2 for n<=25

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..191