A187987 Number of nondecreasing arrangements of n numbers x(i) in -(n+6)..(n+6) with the sum of sign(x(i))*2^|x(i)| zero.

0, 8, 17, 72, 267, 915, 3407, 12148, 43820, 158361, 570132, 2058621, 7429283, 26823311, 96904923, 350182773, 1266059030, 4579170527, 16568732508, 59974168593, 217170088270, 786671363225, 2850611975840, 10333040668513, 37467797814236, 135900958160905

Offset: 1

Author

R. H. Hardin, Mar 18 2011

Keywords

• nonn

Examples

			Some solutions for n=3
.-1...-7...-4...-7...-8...-3...-3...-5...-6...-6...-8...-5...-4...-2...-9...-1
..0....6...-4...-7...-8...-3....2...-5...-6....5....7....4....3...-2....8...-1
..0....6....5....8....9....4....2....6....7....5....7....4....3....3....8....2
		

Crossrefs

Column 8 of A187988.

Extensions

Terms beyond a(11) from R. J. Mathar, May 17 2023