A187982 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, 3, 7, 22, 82, 260, 912, 3158, 10920, 38385, 134652, 474953, 1680801, 5960094, 21192029, 75492493, 269409262, 963003740, 3447075784, 12354841859, 44333177653, 159250306113, 572602762173, 2060689223094, 7422109110741, 26752896159623, 96498088175421, 348296867524920, 1257893866073062, 4545530514677703, 16434464166065112

Offset: 1

Author

R. H. Hardin, Mar 18 2011

Keywords

• nonn

Examples

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

Crossrefs

Column 3 of A187988.

Extensions

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