A187991 Number of nondecreasing arrangements of 7 numbers x(i) in -(n+5)..(n+5) with the sum of sign(x(i))*2^|x(i)| zero.

411, 632, 912, 1257, 1673, 2166, 2742, 3407, 4167, 5028, 5996, 7077, 8277, 9602, 11058, 12651, 14387, 16272, 18312, 20513, 22881, 25422, 28142, 31047, 34143, 37436, 40932, 44637, 48557, 52698

Offset

1,1

Comments

Row 7 of A187988.

Links

Table of n, a(n) for n=1..30.

Example

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

Crossrefs

Sequence in context: A146075 A374270 A212710 * A090123 A055018 A201844

Adjacent sequences: A187988 A187989 A187990 * A187992 A187993 A187994

Keyword

nonn

Author

R. H. Hardin, Mar 18 2011

Extensions

a(26) corrected by R. J. Mathar, May 11 2023

Status

approved