A201041 Number of -7..7 arrays of n elements with adjacent element differences also in -7..7.

15, 169, 1975, 23045, 268983, 3139529, 36644243, 427707523, 4992154799, 58267877227, 680096201983, 7938007456913, 92651542829899, 1081418534229055, 12622197218251193, 147324886317031649, 1719559736948358761

Offset: 1

Author

R. H. Hardin Nov 26 2011

Keywords

• nonn

Comments

Column 7 of A201042

Examples

			Some solutions for n=4
..2...-6....4...-6....6....2...-2....4...-6...-3....7....6....6...-2....4...-3
..0...-6....2...-1....7...-3...-4....1...-3....1....6....0....5...-6....1...-1
..1...-1...-5....6....0....3....3....7...-6...-2....4...-4....1...-3...-2....5
.-5....3...-1....0....3....5....7....4....0....2...-3...-4....1....3...-2....4
		

Links

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

Formula

Empirical: a(n) = 11*a(n-1) +10*a(n-2) -24*a(n-3) -15*a(n-4) +13*a(n-5) +7*a(n-6) -2*a(n-7) -a(n-8)