A281536 Number of nX4 0..2 arrays with no element equal to more than one of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

1, 104, 2919, 15624, 52529, 146956, 385284, 979866, 2440042, 5946178, 14218134, 33491002, 77932633, 179450414, 409349989, 926267006, 2081273523, 4647417316, 10319376525, 22798153410, 50137931781, 109808283414, 239585399751

Offset

1,2

Comments

Column 4 of A281540.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-3) -3*a(n-5) -32*a(n-6) +12*a(n-7) +39*a(n-8) +25*a(n-9) +45*a(n-10) +117*a(n-11) -91*a(n-12) -192*a(n-13) -57*a(n-14) -60*a(n-15) -255*a(n-16) +138*a(n-17) +368*a(n-18) +9*a(n-19) -24*a(n-20) +441*a(n-21) +42*a(n-22) -504*a(n-23) -84*a(n-24) +252*a(n-25) -222*a(n-26) -276*a(n-27) +216*a(n-28) +180*a(n-29) -112*a(n-30) -36*a(n-31) +96*a(n-32) -48*a(n-34) +8*a(n-36) for n>50

Example

Some solutions for n=4
..0..1..2..1. .0..1..0..0. .0..0..1..0. .0..1..2..2. .0..1..1..1
..2..0..1..0. .2..2..2..1. .2..1..2..2. .2..0..1..1. .2..0..0..2
..2..1..2..1. .0..1..1..0. .0..1..0..0. .2..1..2..0. .2..1..2..1
..0..1..0..0. .0..2..0..1. .2..1..2..1. .1..0..1..2. .1..0..0..1

Crossrefs

Cf. A281540.

Sequence in context: A297977 A298840 A298628 * A250684 A299601 A217773

Adjacent sequences: A281533 A281534 A281535 * A281537 A281538 A281539

Keyword

nonn

Author

R. H. Hardin, Jan 23 2017

Status

approved