A303884 Number of nX4 0..1 arrays with every element unequal to 0, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

1, 24, 36, 166, 487, 2130, 7433, 30191, 112815, 444834, 1703258, 6646733, 25671427, 99805187, 386632624, 1501187933, 5821487287, 22593096132, 87646018561, 340100396970, 1319526895683, 5120003868457, 19865539519766, 77080509424841

Offset

1,2

Comments

Column 4 of A303888.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +9*a(n-2) -64*a(n-3) -24*a(n-4) +324*a(n-5) +29*a(n-6) -908*a(n-7) -26*a(n-8) +1535*a(n-9) -63*a(n-10) -1059*a(n-11) -101*a(n-12) -1818*a(n-13) +615*a(n-14) +8168*a(n-15) +1142*a(n-16) -16297*a(n-17) -9152*a(n-18) +17515*a(n-19) +18762*a(n-20) -6862*a(n-21) -11642*a(n-22) -8527*a(n-23) -8707*a(n-24) +6607*a(n-25) +24394*a(n-26) +7559*a(n-27) -25005*a(n-28) -7899*a(n-29) +7951*a(n-30) +8174*a(n-31) -4288*a(n-32) -1081*a(n-33) +1247*a(n-34) -846*a(n-35) +256*a(n-36) +138*a(n-37) -60*a(n-38) for n>41

Example

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

Crossrefs

Cf. A303888.

Sequence in context: A288949 A108190 A185489 * A304616 A172424 A241286

Adjacent sequences: A303881 A303882 A303883 * A303885 A303886 A303887

Keyword

nonn

Author

R. H. Hardin, May 02 2018

Status

approved