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A281135
Number of nX4 0..2 arrays with no element equal to more than one of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
1
2, 112, 1046, 2368, 5368, 12064, 27218, 61508, 137320, 303016, 661750, 1436148, 3102354, 6664604, 14249996, 30349780, 64423304, 136341644, 287731246, 605682872, 1272111378, 2666358192, 5578178044, 11649555816, 24290213802
OFFSET
1,1
COMMENTS
Column 4 of A281139.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-4) -19*a(n-6) -8*a(n-7) +4*a(n-8) +2*a(n-9) +5*a(n-10) +44*a(n-11) +14*a(n-12) -20*a(n-13) +3*a(n-14) +20*a(n-15) -40*a(n-16) -36*a(n-17) +16*a(n-18) +12*a(n-19) -16*a(n-20) +16*a(n-22) -4*a(n-24) for n>33
EXAMPLE
Some solutions for n=4
..0..1..2..0. .0..1..0..0. .0..1..0..0. .0..1..1..2. .0..0..1..0
..2..0..2..0. .2..1..2..1. .2..2..1..2. .0..2..0..0. .1..2..1..2
..2..1..1..1. .0..2..0..0. .0..0..1..0. .1..1..2..2. .0..0..1..0
..0..0..2..2. .0..1..1..2. .1..2..2..0. .0..2..0..0. .1..2..2..0
CROSSREFS
Cf. A281139.
Sequence in context: A231278 A117698 A274057 * A173214 A341782 A024341
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 15 2017
STATUS
approved