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A304351
Number of nX4 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 king-move adjacent elements, with upper left element zero.
1
5, 21, 27, 101, 333, 1023, 4370, 19555, 81921, 373236, 1746093, 7958693, 36661588, 170702565, 790337639, 3658576294, 16987088609, 78814582035, 365464383814, 1695764465465, 7868567868165, 36503556231992, 169363215538143
OFFSET
1,1
COMMENTS
Column 4 of A304355.
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) -18*a(n-2) +49*a(n-3) -269*a(n-4) +408*a(n-5) -265*a(n-6) +2717*a(n-7) -3790*a(n-8) -16*a(n-9) -14852*a(n-10) +13280*a(n-11) +5363*a(n-12) +50241*a(n-13) +13605*a(n-14) -24582*a(n-15) -78178*a(n-16) -168628*a(n-17) +74779*a(n-18) -427247*a(n-19) +528370*a(n-20) -261246*a(n-21) +1276701*a(n-22) -505373*a(n-23) +1837011*a(n-24) -192018*a(n-25) -436735*a(n-26) -1576929*a(n-27) -4089044*a(n-28) +544733*a(n-29) -2626019*a(n-30) -2004790*a(n-31) +2356329*a(n-32) +3393585*a(n-33) +4369119*a(n-34) +4738969*a(n-35) +538806*a(n-36) +362782*a(n-37) +1766911*a(n-38) -8777745*a(n-39) -2596024*a(n-40) +508155*a(n-41) -6901452*a(n-42) +6150100*a(n-43) +13213013*a(n-44) +2645674*a(n-45) +3657655*a(n-46) +5059706*a(n-47) -5941236*a(n-48) -790156*a(n-49) -996420*a(n-50) -6468964*a(n-51) -1031773*a(n-52) +486188*a(n-53) -1940070*a(n-54) +1523221*a(n-55) +1491279*a(n-56) -635330*a(n-57) +27435*a(n-58) +515110*a(n-59) +40654*a(n-60) -106936*a(n-61) -20826*a(n-62) +6718*a(n-63) +1534*a(n-64) -148*a(n-65) -24*a(n-66) for n>69
EXAMPLE
Some solutions for n=5
..0..0..1..1. .0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..0..0
..0..1..1..1. .1..0..0..1. .0..0..0..0. .0..0..1..1. .0..1..0..0
..1..1..1..1. .0..1..1..1. .0..0..0..0. .1..0..1..1. .1..1..1..0
..1..1..1..1. .1..0..1..1. .0..0..0..1. .1..0..1..1. .1..1..0..0
..1..0..1..1. .0..0..1..0. .0..0..0..0. .0..0..1..0. .1..0..0..0
CROSSREFS
Cf. A304355.
Sequence in context: A302305 A351325 A303965 * A305914 A303036 A305343
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 11 2018
STATUS
approved