A187990 Number of nondecreasing arrangements of 6 numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.

67, 117, 181, 260, 355, 467, 597, 746, 915, 1105, 1317, 1552, 1811, 2095, 2405, 2742, 3107, 3501, 3925, 4380, 4867, 5387, 5941, 6530, 7155, 7817, 8517, 9256, 10035, 10855, 11717, 12622, 13571, 14565, 15605, 16692, 17827, 19011, 20245, 21530, 22867, 24257

Offset: 0

Author

R. H. Hardin, Mar 18 2011

Keywords

• nonn
• easy

Examples

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

Links

• Manuel Kauers and Christoph Koutschan, Table of n, a(n) for n = 0..1000 (terms 1..50 from R. H. Hardin).
• M. Kauers and C. Koutschan, Some D-finite and some possibly D-finite sequences in the OEIS, arXiv:2303.02793 [cs.SC], 2023.
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Crossrefs

Row 6 of A187988.

Formula

a(n) = (n^3 + 39*n^2 + 260*n + 402)/6. - Manuel Kauers and Christoph Koutschan, Mar 01 2023

G.f.: -(-67+151*x-115*x^2+30*x^3)/(x-1)^4. - R. J. Mathar, Apr 30 2023

Extensions

a(27) corrected by Manuel Kauers and Christoph Koutschan, Mar 01 2023