A248458 Number of length n+2 0..5 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

174, 862, 4272, 21182, 105026, 520788, 2582406, 12805334, 63497776, 314866606, 1561330890, 7742183252, 38391228334, 190370917646, 943993962960, 4680991358518, 23211674211122, 115099939580084, 570747116572614

Offset: 1

Author

R. H. Hardin, Oct 06 2014

Keywords

• nonn

Comments

Column 5 of A248461

Examples

			Some solutions for n=5
..0....0....0....0....4....4....4....2....3....3....4....0....3....4....1....4
..2....4....1....0....4....0....2....4....2....0....1....3....1....1....0....4
..0....5....0....4....3....5....5....2....0....2....5....4....4....1....3....0
..2....4....3....0....4....0....1....2....5....0....5....4....5....4....5....4
..2....1....0....0....4....5....5....3....1....3....0....0....2....1....5....3
..4....1....1....4....5....1....0....2....2....0....0....3....2....3....0....4
..4....2....3....3....4....4....3....5....2....4....3....4....3....3....3....4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) +10*a(n-2) +11*a(n-3) -32*a(n-4) -119*a(n-5) -139*a(n-6) -26*a(n-7) +126*a(n-8) +130*a(n-9) +28*a(n-10) -12*a(n-11) -4*a(n-12)