A225999 Number of pairs of orthogonal (-1,7) vectors of length 8*n.

520, 14162160, 778340380576, 18604134178857920, 459346524767252653440, 14452627739116790817780480, 429730376813858492544466736640, 12361758128173322901773061686443008

Offset

1,1

Comments

Row 13 of A225987.

Links

R. H. Hardin, Table of n, a(n) for n = 1..58

Example

Some solutions for n=1
.-1..7...-1..7...-1..7...-1..7...-1..7...-1..7...-1..7...-1..7...-1..7...-1..7
..7..7...-1..7....7..7...-1..7...-1..7....7.-1....7.-1....7..7....7..7....7.-1
..7.-1...-1..7...-1..7....7.-1....7.-1....7.-1...-1..7...-1..7...-1..7...-1..7
..7.-1....7.-1...-1..7....7..7....7.-1...-1..7....7..7....7.-1....7.-1....7..7
..7.-1....7.-1...-1..7....7.-1...-1..7....7.-1....7.-1....7.-1....7.-1....7.-1
.-1..7....7..7....7.-1....7.-1...-1..7...-1..7...-1..7...-1..7....7.-1...-1..7
..7.-1....7.-1....7.-1...-1..7...-1..7....7.-1....7.-1...-1..7...-1..7...-1..7
..7.-1....7.-1...-1..7....7.-1....7..7....7..7....7.-1...-1..7...-1..7....7.-1

Crossrefs

Sequence in context: A168220 A293105 A286977 * A291998 A300395 A139663

Adjacent sequences: A225996 A225997 A225998 * A226000 A226001 A226002

Keyword

nonn

Author

R. H. Hardin, May 22 2013

Status

approved