A184235 Number of strings of numbers x(i=1..n) in 0..4 with sum i^2*x(i)^2 equal to n^2*16.

1, 1, 1, 1, 3, 15, 31, 119, 555, 2138, 9548, 33391, 136682, 468971, 1753525, 5789709, 19745186, 63565260, 203046061, 638284176, 1947963410, 5979604119, 17725544038, 53252284414, 155128241215, 456635560332, 1314718658955, 3796821176997

Offset: 1

Author

R. H. Hardin Jan 10 2011

Keywords

• nonn

Comments

Column 4 of A184240

Examples

			All solutions for n=5
..2....0....0
..1....0....0
..2....4....0
..4....4....0
..2....0....4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..39