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A283780
Number of nX4 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements.
1
0, 14, 625, 10910, 174447, 2510456, 33933330, 439118692, 5498459845, 67121993862, 802882295057, 9444916323342, 109571555114744, 1256227000217798, 14257060902385365, 160383949024164060, 1790320360619426367
OFFSET
1,2
COMMENTS
Column 4 of A283784.
LINKS
FORMULA
Empirical: a(n) = 21*a(n-1) -75*a(n-2) -500*a(n-3) -681*a(n-4) +14070*a(n-5) +66834*a(n-6) +139032*a(n-7) -160275*a(n-8) -1405556*a(n-9) -3401838*a(n-10) -791658*a(n-11) +13175067*a(n-12) +36437481*a(n-13) +23855217*a(n-14) -68703699*a(n-15) -216054840*a(n-16) -171287535*a(n-17) +224531338*a(n-18) +760107903*a(n-19) +595077312*a(n-20) -505895393*a(n-21) -1576187241*a(n-22) -1019970015*a(n-23) +756331656*a(n-24) +1728765105*a(n-25) +791098521*a(n-26) -581764517*a(n-27) -828007422*a(n-28) -234508218*a(n-29) +151749818*a(n-30) +120782574*a(n-31) +37179264*a(n-32) +12003673*a(n-33) -692574*a(n-34) -4660656*a(n-35) -2434512*a(n-36) -906336*a(n-37) -352896*a(n-38) -94208*a(n-39) -17664*a(n-40) -3840*a(n-41) -512*a(n-42)
EXAMPLE
Some solutions for n=4
..0..0..1..1. .1..1..0..0. .0..0..0..1. .1..1..0..1. .1..1..0..0
..0..1..1..1. .1..1..0..1. .0..0..1..1. .1..0..1..1. .1..1..0..1
..0..1..0..0. .1..0..1..0. .1..1..1..0. .0..0..1..0. .1..1..0..0
..0..0..0..1. .1..0..1..1. .1..0..1..0. .0..1..0..0. .0..0..0..1
CROSSREFS
Cf. A283784.
Sequence in context: A209678 A280676 A209103 * A210808 A139196 A336513
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 16 2017
STATUS
approved