A305248 Number of nX4 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero.

5, 17, 17, 42, 79, 163, 356, 794, 1699, 3824, 8679, 19781, 44895, 103263, 237666, 548058, 1264630, 2928625, 6784853, 15731354, 36493477, 84743671, 196829622, 457317706, 1062817463, 2470772382, 5744515982, 13357785806, 31064375867

Offset

1,1

Comments

Column 4 of A305252.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) +2*a(n-3) +a(n-4) -23*a(n-5) +32*a(n-6) -28*a(n-7) +37*a(n-8) -21*a(n-9) +a(n-10) +88*a(n-11) -93*a(n-12) +99*a(n-13) -13*a(n-14) -120*a(n-15) -149*a(n-16) +30*a(n-17) +36*a(n-18) -137*a(n-19) +117*a(n-20) +45*a(n-21) +25*a(n-22) +51*a(n-23) +30*a(n-24) -4*a(n-25) -5*a(n-26) for n>30

Example

Some solutions for n=5
..0..0..1..1. .0..1..1..0. .0..0..0..0. .0..0..0..0. .0..1..1..0
..0..1..1..1. .1..1..1..1. .1..0..0..1. .0..0..1..0. .1..1..1..1
..1..1..1..1. .1..1..1..1. .1..0..1..1. .0..0..0..0. .1..1..1..1
..1..1..1..1. .0..1..1..1. .0..0..1..1. .0..0..0..0. .1..0..1..1
..0..1..1..0. .0..0..1..1. .0..0..0..1. .0..0..0..0. .1..1..1..1

Crossrefs

Cf. A305252.

Sequence in context: A128895 A141558 A304217 * A231710 A316548 A275629

Adjacent sequences: A305245 A305246 A305247 * A305249 A305250 A305251

Keyword

nonn

Author

R. H. Hardin, May 28 2018

Status

approved