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A301446
Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
8, 108, 1008, 9541, 91370, 877044, 8414314, 80726964, 774477323, 7430228709, 71284529536, 683893628760, 6561177596757, 62947000071013, 603904519316269, 5793773626269543, 55584635903151286, 533271050607294727
OFFSET
1,1
COMMENTS
Column 4 of A301450.
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) +14*a(n-2) -82*a(n-3) +5*a(n-4) +210*a(n-5) -381*a(n-6) -224*a(n-7) -7*a(n-8) +790*a(n-9) +1112*a(n-10) -5103*a(n-11) +10610*a(n-12) +4283*a(n-13) -18136*a(n-14) +27908*a(n-15) -6641*a(n-16) -12938*a(n-17) +16505*a(n-18) -16973*a(n-19) -38570*a(n-20) +34834*a(n-21) -1406*a(n-22) -24627*a(n-23) +31869*a(n-24) +15063*a(n-25) -23509*a(n-26) +14505*a(n-27) +2202*a(n-28) -9988*a(n-29) -3801*a(n-30) +1439*a(n-31) -3136*a(n-32) +6064*a(n-33) -1559*a(n-34) -428*a(n-35) +1588*a(n-36) -1063*a(n-37) -352*a(n-38) +384*a(n-39) -64*a(n-40)
EXAMPLE
Some solutions for n=5
..0..0..1..0. .0..0..1..0. .0..0..0..1. .0..1..0..1. .0..1..0..0
..1..0..1..0. .0..1..0..1. .1..0..0..1. .0..1..1..0. .0..0..0..1
..0..0..1..0. .0..1..1..1. .0..0..1..1. .0..0..0..1. .1..1..1..0
..0..1..1..1. .0..0..0..1. .1..1..0..0. .0..1..0..1. .0..0..0..0
..1..0..0..1. .1..0..1..1. .1..0..1..0. .0..0..1..0. .1..0..0..1
CROSSREFS
Cf. A301450.
Sequence in context: A300468 A326101 A300807 * A363476 A272497 A215129
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 21 2018
STATUS
approved