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A298715
Number of nX4 0..1 arrays with every element equal to 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.
1
0, 5, 13, 59, 346, 2246, 13650, 87117, 550582, 3489783, 22151146, 140554255, 891978232, 5661362187, 35930336202, 228040023568, 1447314125762, 9185725194376, 58299474631379, 370012068242202, 2348373088230451
OFFSET
1,2
COMMENTS
Column 4 of A298719.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +21*a(n-2) +26*a(n-3) -83*a(n-4) -381*a(n-5) -615*a(n-6) +35*a(n-7) +3867*a(n-8) +7013*a(n-9) -10556*a(n-10) -28387*a(n-11) +36768*a(n-12) +76311*a(n-13) -45835*a(n-14) +3816*a(n-15) +97956*a(n-16) -117608*a(n-17) -52644*a(n-18) -747689*a(n-19) -1709818*a(n-20) -645060*a(n-21) -356415*a(n-22) +1628581*a(n-23) +4221676*a(n-24) +2300743*a(n-25) +1249904*a(n-26) +3932427*a(n-27) +17279908*a(n-28) +9184386*a(n-29) -17055518*a(n-30) +1579068*a(n-31) +5489858*a(n-32) -25487233*a(n-33) -17021794*a(n-34) -4854033*a(n-35) -41985127*a(n-36) -27002556*a(n-37) -21698789*a(n-38) -3750642*a(n-39) -47747959*a(n-40) -17666861*a(n-41) +21595450*a(n-42) -9559888*a(n-43) -13055872*a(n-44) -8853708*a(n-45) +8773297*a(n-46) +25433464*a(n-47) -139020*a(n-48) -17186112*a(n-49) +22110645*a(n-50) -10615240*a(n-51) +6879505*a(n-52) -2098646*a(n-53) +217015*a(n-54) -319802*a(n-55) -196014*a(n-56) -101709*a(n-57) +40087*a(n-58) +18226*a(n-59) -14278*a(n-60) +4444*a(n-61) -144*a(n-62) -768*a(n-63) for n>64
EXAMPLE
Some solutions for n=7
..0..0..0..0. .0..0..1..1. .0..0..0..0. .0..0..0..0. .0..0..1..1
..0..1..0..1. .0..1..1..0. .0..0..1..0. .0..1..1..0. .0..0..0..1
..1..1..1..1. .1..0..0..0. .1..1..1..1. .1..0..1..0. .0..1..0..1
..1..1..1..1. .1..1..1..0. .1..1..1..1. .1..0..0..0. .1..1..1..1
..1..0..0..1. .1..1..1..0. .1..0..1..0. .1..0..0..0. .1..1..1..1
..0..0..1..1. .1..0..1..0. .1..0..0..0. .1..0..1..1. .1..0..0..1
..0..0..0..1. .0..0..0..0. .1..1..0..0. .1..1..1..1. .0..0..0..0
CROSSREFS
Cf. A298719.
Sequence in context: A149565 A149566 A298066 * A380084 A006701 A071699
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 25 2018
STATUS
approved