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A300634
Number of nX3 0..1 arrays with every element equal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
1, 6, 13, 34, 91, 253, 705, 1978, 5507, 15222, 41977, 115897, 320655, 888366, 2462325, 6824338, 18907933, 52373153, 145049587, 401721354, 1112657323, 3081952434, 8537004059, 23647611701, 65503496945, 181441284654, 502578971705
OFFSET
1,2
COMMENTS
Column 3 of A300639.
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) -19*a(n-2) +28*a(n-3) -32*a(n-4) +42*a(n-5) -43*a(n-6) +23*a(n-7) -29*a(n-8) +16*a(n-9) +12*a(n-10) +64*a(n-11) +58*a(n-12) -110*a(n-13) -198*a(n-14) -136*a(n-15) +100*a(n-16) +236*a(n-17) +198*a(n-18) +90*a(n-19) +30*a(n-20) -16*a(n-21) -76*a(n-22) -64*a(n-23) +7*a(n-24) +23*a(n-25) -7*a(n-26) -20*a(n-27) -4*a(n-28) +10*a(n-29) +5*a(n-30) -a(n-31) -a(n-32)
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..1. .0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..0
..1..1..0. .1..1..1. .1..1..0. .0..0..1. .0..1..1. .1..1..1. .1..1..1
..1..0..1. .1..0..0. .0..1..0. .0..1..0. .1..1..1. .0..0..0. .0..0..1
..0..1..0. .0..1..1. .0..1..1. .1..0..1. .0..0..0. .1..1..1. .1..0..0
..0..1..0. .0..0..1. .0..0..0. .0..1..1. .1..1..1. .0..0..1. .1..1..0
CROSSREFS
Cf. A300639.
Sequence in context: A048693 A041068 A300430 * A301356 A037243 A107710
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 10 2018
STATUS
approved