A245948 Number of length n+3 0..6 arrays with some pair in every consecutive four terms totalling exactly 6.

1435, 7669, 39721, 199141, 1021225, 5208673, 26526337, 135336793, 690045061, 3518298991, 17940920173, 91480646389, 466463146399, 2378531818147, 12128251046821, 61842638080231, 315339231002215, 1607932492222021

Offset: 1

Author

R. H. Hardin, Aug 08 2014

Keywords

• nonn

Comments

Column 6 of A245950.

Examples

			Some solutions for n=4
..3....4....0....4....0....1....3....4....4....1....0....4....4....3....1....4
..6....5....5....6....2....4....2....5....3....1....1....1....3....6....4....1
..1....4....6....1....4....2....3....1....2....4....0....5....3....5....6....1
..0....1....5....0....5....5....4....5....4....2....6....6....3....1....0....5
..6....4....1....6....6....0....2....6....5....4....2....1....3....0....1....3
..6....5....4....2....0....6....2....2....5....0....4....2....1....0....0....1
..1....2....5....1....4....2....1....4....1....4....1....0....2....6....5....5
		

Links

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

Crossrefs

Cf. A245950.

Formula

Empirical: a(n) = 4*a(n-1) +8*a(n-2) +2*a(n-3) -39*a(n-4) -139*a(n-5) -175*a(n-6) -179*a(n-7) +980*a(n-8) +1638*a(n-9) -1266*a(n-10) -210*a(n-11) -352*a(n-12) +123*a(n-13) +24*a(n-14) +19*a(n-15) -5*a(n-16).