A207098 Number of 0..6 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 7.

7, 28, 112, 462, 1904, 7868, 32531, 134517, 556259, 2300219, 9511719, 39332200, 162643507, 672550879, 2781080236, 11500107101, 47554350602, 196643061212, 813143132135, 3362446402726, 13904127534002, 57495269615906

Offset: 1

Author

R. H. Hardin, Feb 15 2012

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 6 of A207100.

Formula

Empirical: a(n) = 4*a(n-1) +3*a(n-2) -9*a(n-3) -8*a(n-4) +12*a(n-5) +11*a(n-6) -6*a(n-7) +5*a(n-8) -2*a(n-9) -17*a(n-10) +3*a(n-11) -4*a(n-12) -4*a(n-13) +a(n-14) -2*a(n-15) +9*a(n-16) -12*a(n-17) -a(n-18) +10*a(n-19) -19*a(n-20) -9*a(n-21) +7*a(n-22) -4*a(n-23) -3*a(n-24) +4*a(n-25) +14*a(n-26) +5*a(n-28) +11*a(n-29) +a(n-30) -a(n-31) -a(n-32) +8*a(n-33) +2*a(n-34) -a(n-35) +5*a(n-36) -2*a(n-37) -2*a(n-38) -a(n-40) -3*a(n-42) -a(n-43) -a(n-44) -a(n-49).