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A304415
Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.
2
1, 24, 103, 835, 7017, 60245, 522349, 4542604, 39567170, 344867709, 3006637339, 26216229524, 228603730278, 1993460011680, 17383499694996, 151589509899903, 1321910981585320, 11527517181690855, 100523956632846546
OFFSET
1,2
COMMENTS
Column 4 of A304419.
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) +18*a(n-2) -126*a(n-3) -642*a(n-4) +947*a(n-5) +5892*a(n-6) +3421*a(n-7) -22541*a(n-8) -42456*a(n-9) -1502*a(n-10) +84330*a(n-11) +92320*a(n-12) +84252*a(n-13) +179487*a(n-14) +61076*a(n-15) -686553*a(n-16) -1365118*a(n-17) -335218*a(n-18) +1910366*a(n-19) +2465234*a(n-20) -56719*a(n-21) -2858935*a(n-22) -3505136*a(n-23) -1217142*a(n-24) +2480294*a(n-25) +4393672*a(n-26) +2089476*a(n-27) -2038851*a(n-28) -2486979*a(n-29) +312720*a(n-30) +1131502*a(n-31) +154965*a(n-32) +141350*a(n-33) +726963*a(n-34) +185495*a(n-35) -603585*a(n-36) -371131*a(n-37) +146974*a(n-38) +296513*a(n-39) +79957*a(n-40) -44532*a(n-41) -43568*a(n-42) -3508*a(n-43) +6980*a(n-44) +80*a(n-46) +128*a(n-47) for n>48
EXAMPLE
Some solutions for n=5
..0..1..0..1. .0..1..1..0. .0..0..1..0. .0..1..1..0. .0..1..0..0
..0..1..1..0. .1..0..1..1. .1..1..1..0. .0..1..1..0. .1..1..1..1
..0..1..1..0. .0..1..0..0. .0..1..0..0. .0..0..1..1. .0..0..0..0
..1..0..0..0. .1..1..0..0. .1..0..1..0. .0..1..1..0. .0..0..1..1
..0..1..1..1. .0..0..1..1. .0..1..1..0. .1..0..0..1. .1..1..1..0
CROSSREFS
Cf. A304419.
Sequence in context: A269047 A182675 A100155 * A268804 A186932 A275506
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 12 2018
STATUS
approved