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

1,1

Links

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

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).

Example

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

Crossrefs

Column 6 of A207100.

Sequence in context: A200467 A002042 A200666 * A037597 A037702 A359018

Adjacent sequences: A207095 A207096 A207097 * A207099 A207100 A207101

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved