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A306138
Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.
1
1, 23, 90, 521, 2787, 14804, 79839, 428041, 2296512, 12329851, 66162665, 355098680, 1905814101, 10228215869, 54894290098, 294613084651, 1581163788591, 8485982858500, 45543581015859, 244428741410877, 1311829444865816
OFFSET
1,2
COMMENTS
Column 3 of A306143.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +11*a(n-2) +16*a(n-3) -34*a(n-4) -20*a(n-5) +28*a(n-6) -49*a(n-8) -17*a(n-9) +37*a(n-10) -2*a(n-11) -36*a(n-12) -56*a(n-13) -16*a(n-14) +16*a(n-15) for n>16
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..1. .0..0..0. .0..1..0. .0..1..1. .0..1..0. .0..1..1
..0..1..0. .1..1..0. .1..0..1. .1..0..1. .1..1..0. .0..1..1. .0..0..1
..0..0..0. .1..0..0. .1..0..1. .1..0..0. .1..0..0. .0..0..0. .1..0..0
..1..1..0. .0..1..0. .1..1..0. .0..0..1. .0..1..0. .0..1..1. .1..0..0
..0..0..0. .0..0..0. .0..0..1. .1..0..1. .0..0..1. .0..1..0. .0..0..1
CROSSREFS
Cf. A306143.
Sequence in context: A142062 A050529 A215613 * A317371 A244632 A042030
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 22 2018
STATUS
approved