A246001 Number of length 6+2 0..n arrays with no pair in any consecutive three terms totalling exactly n.

2, 56, 2308, 23168, 171942, 795144, 3057032, 9401216, 25819210, 62402840, 139927692, 288998016, 566057198, 1047126248, 1862251792, 3175741184, 5253738642, 8416795896, 13163097620, 20070807680, 30009814582, 43960191176

Offset: 1

Author

R. H. Hardin, Aug 09 2014

Keywords

• nonn

Comments

Row 6 of A245995.

Examples

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

Links

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

Crossrefs

Cf. A245995.

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-2) -17*a(n-3) +3*a(n-4) +39*a(n-5) -25*a(n-6) -45*a(n-7) +45*a(n-8) +25*a(n-9) -39*a(n-10) -3*a(n-11) +17*a(n-12) -3*a(n-13) -3*a(n-14) +a(n-15).