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A305248
Number of nX4 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero.
1
5, 17, 17, 42, 79, 163, 356, 794, 1699, 3824, 8679, 19781, 44895, 103263, 237666, 548058, 1264630, 2928625, 6784853, 15731354, 36493477, 84743671, 196829622, 457317706, 1062817463, 2470772382, 5744515982, 13357785806, 31064375867
OFFSET
1,1
COMMENTS
Column 4 of A305252.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -4*a(n-2) +2*a(n-3) +a(n-4) -23*a(n-5) +32*a(n-6) -28*a(n-7) +37*a(n-8) -21*a(n-9) +a(n-10) +88*a(n-11) -93*a(n-12) +99*a(n-13) -13*a(n-14) -120*a(n-15) -149*a(n-16) +30*a(n-17) +36*a(n-18) -137*a(n-19) +117*a(n-20) +45*a(n-21) +25*a(n-22) +51*a(n-23) +30*a(n-24) -4*a(n-25) -5*a(n-26) for n>30
EXAMPLE
Some solutions for n=5
..0..0..1..1. .0..1..1..0. .0..0..0..0. .0..0..0..0. .0..1..1..0
..0..1..1..1. .1..1..1..1. .1..0..0..1. .0..0..1..0. .1..1..1..1
..1..1..1..1. .1..1..1..1. .1..0..1..1. .0..0..0..0. .1..1..1..1
..1..1..1..1. .0..1..1..1. .0..0..1..1. .0..0..0..0. .1..0..1..1
..0..1..1..0. .0..0..1..1. .0..0..0..1. .0..0..0..0. .1..1..1..1
CROSSREFS
Cf. A305252.
Sequence in context: A128895 A141558 A304217 * A231710 A316548 A275629
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 28 2018
STATUS
approved