A225993 Number of pairs of orthogonal (-1,5) vectors of length 6*n.

102, 211332, 720120000, 1722187940880, 4204143930847392, 11097567635368456704, 29480432084171748705792, 78401556201196275000295680, 210537848971493804380009055232, 569368618586592872585662539389952

Offset: 1

Author

R. H. Hardin, May 22 2013

Keywords

• nonn

Comments

Row 7 of A225987.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..91