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A298135
Number of nX4 0..1 arrays with every element equal to 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero.
1
0, 2, 3, 10, 20, 68, 185, 561, 1600, 4856, 14490, 43334, 130046, 390291, 1172586, 3523139, 10593181, 31854446, 95807649, 288198019, 867005085, 2608469794, 7848188504, 23614061363, 71053102045, 213798191069, 643325960937
OFFSET
1,2
COMMENTS
Column 4 of A298139.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) -5*a(n-2) +a(n-3) -19*a(n-4) +15*a(n-5) +77*a(n-7) -84*a(n-8) +104*a(n-9) -175*a(n-10) +237*a(n-11) -444*a(n-12) +166*a(n-13) -252*a(n-14) +783*a(n-15) -239*a(n-16) -923*a(n-17) +47*a(n-18) -1198*a(n-19) +4530*a(n-20) -2018*a(n-21) +8752*a(n-22) -12503*a(n-23) +11509*a(n-24) -11694*a(n-25) +12104*a(n-26) -39091*a(n-27) +11361*a(n-28) +13063*a(n-29) +25473*a(n-30) -18499*a(n-31) -14521*a(n-32) +40263*a(n-33) -2644*a(n-34) -22026*a(n-35) -35689*a(n-36) +31132*a(n-37) +18644*a(n-38) +6559*a(n-39) -15323*a(n-40) -3234*a(n-41) -21417*a(n-42) -5870*a(n-43) +16627*a(n-44) +9301*a(n-45) +860*a(n-46) -5387*a(n-47) +839*a(n-48) +447*a(n-49) +1998*a(n-50) -1505*a(n-51) -218*a(n-52) -195*a(n-53) +391*a(n-54) -74*a(n-55) -24*a(n-56) -48*a(n-57) +28*a(n-58) +8*a(n-59) -4*a(n-60) for n>61
EXAMPLE
Some solutions for n=7
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0
..0..1..1..0. .0..1..1..0. .0..1..1..0. .0..1..1..0. .0..1..1..0
..0..1..0..1. .1..0..1..0. .1..0..1..0. .1..0..0..1. .1..0..0..1
..0..0..0..1. .1..0..1..0. .1..1..0..0. .1..1..1..0. .1..1..1..0
..0..1..1..0. .0..1..1..0. .1..0..1..0. .0..0..0..1. .1..0..1..0
..1..0..0..1. .1..0..1..0. .1..0..1..0. .0..1..1..0. .1..0..0..1
..1..1..1..1. .1..1..0..0. .1..1..0..0. .1..1..0..0. .1..1..1..1
CROSSREFS
Cf. A298139.
Sequence in context: A148055 A089791 A297872 * A226356 A141050 A354720
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 13 2018
STATUS
approved