A304844 Number of n X 4 0..1 arrays with every element unequal to 0, 1, 2, 4 or 7 king-move adjacent elements, with upper left element zero.

8, 24, 51, 132, 502, 1638, 4816, 15697, 51711, 162366, 515716, 1666971, 5329280, 16966976, 54361108, 174123735, 556206198, 1778536970, 5692126701, 18203527304, 58206977546, 186193045751, 595556243811, 1904654103039, 6091785970264

Offset

1,1

Comments

Column 4 of A304848.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +10*a(n-3) -12*a(n-4) -70*a(n-5) -57*a(n-6) +109*a(n-7) +258*a(n-8) +80*a(n-9) -206*a(n-10) -210*a(n-11) -54*a(n-12) -493*a(n-13) -200*a(n-14) +1067*a(n-15) +336*a(n-16) -258*a(n-17) +16*a(n-18) +129*a(n-19) +71*a(n-20) -951*a(n-21) -578*a(n-22) +1082*a(n-23) -246*a(n-24) +3*a(n-25) +1259*a(n-26) -962*a(n-27) -842*a(n-28) +848*a(n-29) -98*a(n-30) -294*a(n-31) +282*a(n-32) +48*a(n-33) -72*a(n-34) for n > 38.

Example

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

Crossrefs

Cf. A304848.

Sequence in context: A358036 A068857 A064225 * A054275 A256857 A122655

Adjacent sequences: A304841 A304842 A304843 * A304845 A304846 A304847

Keyword

nonn

Author

R. H. Hardin, May 19 2018

Status

approved