A225996 Number of pairs of orthogonal (-4,5) vectors of length 9*n.

3024, 1596291840, 294038117867520, 68184361565718773760, 16084808323123050319970304, 3830251318099321155852479496192, 931823480133178593246564251905032192

Offset

1,1

Comments

Row 10 of A225987.

Links

R. H. Hardin, Table of n, a(n) for n = 1..56

Example

Some solutions for n=1
..5..5....5..5...-4..5...-4..5...-4..5...-4..5...-4.-4...-4..5...-4..5...-4..5
.-4..5....5..5...-4..5...-4.-4....5..5...-4..5...-4..5...-4.-4...-4.-4....5..5
.-4..5...-4..5....5..5....5.-4....5.-4....5..5...-4..5...-4.-4...-4.-4...-4..5
..5..5....5.-4....5..5...-4.-4....5..5...-4..5...-4.-4....5.-4...-4..5...-4..5
..5.-4....5..5....5.-4...-4..5....5..5...-4..5...-4.-4....5.-4....5.-4...-4..5
.-4..5...-4..5....5..5...-4..5....5.-4....5..5...-4..5...-4.-4...-4.-4....5..5
..5..5...-4..5....5..5...-4.-4....5.-4....5..5...-4.-4...-4.-4...-4.-4....5..5
.-4..5...-4..5....5.-4...-4.-4....5..5....5..5...-4.-4...-4.-4...-4.-4....5.-4
..5..5....5..5....5.-4...-4.-4...-4..5...-4..5....5.-4...-4..5....5.-4....5..5

Crossrefs

Sequence in context: A255736 A231762 A034600 * A167044 A221249 A038544

Adjacent sequences: A225993 A225994 A225995 * A225997 A225998 A225999

Keyword

nonn

Author

R. H. Hardin, May 22 2013

Status

approved