A304220 Number of nX7 0..1 arrays with every element unequal to 0, 1, 3 or 8 king-move adjacent elements, with upper left element zero.

21, 103, 93, 190, 509, 1628, 4263, 11307, 32315, 89108, 241808, 671482, 1860876, 5112838, 14112560, 39021398, 107604674, 296850358, 819720184, 2262238142, 6242240358, 17229841514, 47554661392, 131237610194, 362206032762

Offset

1,1

Comments

Column 7 of A304221.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +10*a(n-3) +5*a(n-4) -2*a(n-5) -13*a(n-6) -16*a(n-7) -8*a(n-8) +10*a(n-9) +22*a(n-10) +9*a(n-11) -20*a(n-12) -22*a(n-13) -4*a(n-14) +14*a(n-15) +12*a(n-16) +6*a(n-17) -6*a(n-18) for n>24

Example

Some solutions for n=7
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0
..0..0..0..0..0..1..0. .0..0..0..0..1..0..0. .0..0..1..0..0..0..0
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..1
..0..0..0..0..0..0..0. .0..1..0..0..0..0..0. .0..0..0..0..0..1..1
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..1..1..1
..1..0..0..0..0..1..0. .0..0..0..0..0..1..0. .0..0..0..1..1..1..1
..1..1..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..1..1..1..1..1

Crossrefs

Cf. A304221.

Sequence in context: A208538 A303681 A304132 * A305481 A219385 A219297

Adjacent sequences: A304217 A304218 A304219 * A304221 A304222 A304223

Keyword

nonn

Author

R. H. Hardin, May 08 2018

Status

approved