A187983 Number of nondecreasing arrangements of n numbers x(i) in -(n+2)..(n+2) with the sum of sign(x(i))*2^|x(i)| zero.

0, 4, 9, 30, 111, 355, 1257, 4357, 15146, 53379, 187699, 663631, 2352610, 8356208, 29754352, 106127185, 379166226, 1356700796, 4860763378, 17436188166, 62613987171, 225072940410, 809789751003, 2915986488761, 10508369260118, 37896284981596, 136756217644237, 493817776063606

Offset: 1

Author

R. H. Hardin, Mar 18 2011

Keywords

• nonn

Examples

			All solutions for n=3
.-2...-3...-4...-1...-1...-4...-5...-2...-3
.-2...-3....3...-1....0...-4....4....1....2
..3....4....3....2....0....5....4....1....2
		

Crossrefs

Column 4 of A187988.

Extensions

Terms from a(16) on by R. J. Mathar, May 17 2023