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A304890
Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.
2
1, 24, 40, 246, 899, 4262, 18773, 86217, 393045, 1797614, 8250018, 37806949, 173560449, 796357535, 3655798608, 16780585631, 77034933529, 353640484316, 1623486194095, 7453088205576, 34215785172369, 157078858232301
OFFSET
1,2
COMMENTS
Column 4 of A304894.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +11*a(n-2) -50*a(n-3) -107*a(n-4) +164*a(n-5) +708*a(n-6) +258*a(n-7) -2532*a(n-8) -3646*a(n-9) +2761*a(n-10) +13804*a(n-11) +8446*a(n-12) -21154*a(n-13) -47250*a(n-14) -10914*a(n-15) +107499*a(n-16) +142066*a(n-17) -105426*a(n-18) -363420*a(n-19) -154022*a(n-20) +480595*a(n-21) +608522*a(n-22) -60692*a(n-23) -841802*a(n-24) -653368*a(n-25) +308330*a(n-26) +953192*a(n-27) +471156*a(n-28) -518499*a(n-29) -662721*a(n-30) -5905*a(n-31) +315496*a(n-32) +93165*a(n-33) -26826*a(n-34) +40184*a(n-35) -12298*a(n-36) -84979*a(n-37) -21668*a(n-38) +49569*a(n-39) +20751*a(n-40) -16407*a(n-41) -7208*a(n-42) +3391*a(n-43) +1365*a(n-44) -413*a(n-45) -170*a(n-46) +30*a(n-47) +12*a(n-48) -2*a(n-49) for n>52
EXAMPLE
Some solutions for n=5
..0..1..0..1. .0..0..0..1. .0..1..1..1. .0..0..0..1. .0..0..0..1
..1..1..1..0. .0..0..0..1. .0..1..1..1. .1..1..1..0. .1..1..0..1
..0..1..1..1. .1..1..1..0. .1..0..0..0. .1..1..1..0. .0..0..0..1
..0..1..1..0. .0..1..1..0. .0..0..1..0. .1..1..1..1. .0..1..0..0
..0..1..0..1. .1..0..0..1. .1..0..0..1. .0..0..0..0. .1..0..0..1
CROSSREFS
Cf. A304894.
Sequence in context: A185742 A286876 A181702 * A264155 A241254 A376421
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 20 2018
STATUS
approved