A200250 Number of 0..7 arrays x(0..n-1) of n elements with each no smaller than the sum of its previous elements modulo 8.

8, 36, 164, 750, 3434, 15724, 71970, 329455, 1508139, 6903702, 31602661, 144665637, 662227235, 3031438038, 13876832881, 63523149100, 290786125630, 1331114279973, 6093362338144, 27893220846536, 127685131134366, 584496598744029

Offset: 1

Author

R. H. Hardin, Nov 15 2011

Keywords

• nonn

Comments

Column 7 of A200251.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..134

Crossrefs

Cf. A200251.

Formula

Empirical: a(n) = a(n-1) +9*a(n-2) +24*a(n-3) +36*a(n-4) +35*a(n-5) +21*a(n-6) +7*a(n-7) +a(n-8).

Empirical g.f.: x*(2 + x)*(2 + 2*x + x^2)*(2 + 4*x + 6*x^2 + 4*x^3 + x^4) / (1 - x - 9*x^2 - 24*x^3 - 36*x^4 - 35*x^5 - 21*x^6 - 7*x^7 - x^8). - Colin Barker, May 20 2018