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A230737 Number of (n+3)X(4+3) 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero 1
102, 2016, 16536, 320970, 2382398, 46599682, 342031378, 6692078688, 49068380730, 959928337654, 7037607186036, 137677370665624, 1009342929539188, 19745940646875492, 144761390761971996, 2831990839783724564 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A230739

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 185*a(n-2) -6851*a(n-4) +145707*a(n-6) -2849231*a(n-8) +30720183*a(n-10) -36007996*a(n-12) -743385180*a(n-14) +287330815*a(n-16) +8627923017*a(n-18) -12118273932*a(n-20) -29408445279*a(n-22) +45675171837*a(n-24) -13807146112*a(n-26) -2411662568755*a(n-28) +3802259458200*a(n-30) +3456476952882*a(n-32) +4249525502473*a(n-34) -5769431443156*a(n-36) -7037014662528*a(n-38) +2632063276930*a(n-40) +18416679443602*a(n-42) +9430615399362*a(n-44) +259673859628*a(n-46) +64576080600*a(n-48) +325261872*a(n-50)

EXAMPLE

Some solutions for n=3

..x..0..x..1..x..1..x....x..0..x..0..x..0..x....x..0..x..1..x..1..x

..1..x..0..x..2..x..2....2..x..1..x..1..x..1....1..x..0..x..2..x..2

..x..2..x..2..x..0..x....x..2..x..0..x..2..x....x..2..x..2..x..0..x

..2..x..1..x..1..x..2....1..x..0..x..0..x..1....0..x..2..x..1..x..2

..x..0..x..0..x..1..x....x..0..x..1..x..2..x....x..1..x..0..x..1..x

..2..x..2..x..0..x..0....2..x..2..x..0..x..1....0..x..2..x..2..x..0

CROSSREFS

Sequence in context: A206651 A163435 A223308 * A203401 A217331 A284448

Adjacent sequences:  A230734 A230735 A230736 * A230738 A230739 A230740

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 28 2013

STATUS

approved

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Last modified July 11 15:58 EDT 2020. Contains 335626 sequences. (Running on oeis4.)