A187980 Number of nondecreasing arrangements of n numbers x(i) in -(n-1)..(n-1) with the sum of sign(x(i))*2^|x(i)| zero

0, 1, 3, 9, 36, 117, 411, 1452, 5040, 17829, 62870, 222458, 789895, 2808018, 10006020, 35713288, 127657287, 456975112, 1637845137, 5876993799, 21110257429, 75900966585, 273140226328, 983733709424, 3545658087397, 12788512426396, 46155740640489, 166684398100813, 602296651467057, 2177492178467267, 7876245417001355

Offset

1,3

Comments

Column 1 of A187988

Links

Table of n, a(n) for n=1..31.

Example

All solutions for n=3
.-1...-2...-1
.-1....1....0
..2....1....0

Crossrefs

Sequence in context: A125792 A223310 A149020 * A057390 A183495 A185162

Adjacent sequences: A187977 A187978 A187979 * A187981 A187982 A187983

Keyword

nonn

Author

R. H. Hardin Mar 18 2011

Extensions

More terms from R. J. Mathar, May 11 2023

Status

approved