A212780 Half the number of 0..6 arrays of length n+2 with second differences nonzero.

159, 1034, 6724, 43727, 284360, 1849215, 12025596, 78203437, 508563345, 3307229006, 21507180645, 139862954332, 909540228150, 5914814473647, 38464522156756, 250137932701244, 1626667429300337, 10578351299907331

Offset: 1

Author

R. H. Hardin May 27 2012

Keywords

• nonn

Comments

Column 6 of A212782

Examples

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

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +15*a(n-2) +39*a(n-3) +66*a(n-4) +65*a(n-5) -3*a(n-6) -107*a(n-7) -162*a(n-8) -136*a(n-9) -96*a(n-10) -71*a(n-11) -31*a(n-12) -4*a(n-13)