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A298578
Number of nX4 0..1 arrays with every element equal to 1, 2, 4, 5 or 7 king-move adjacent elements, with upper left element zero.
1
2, 13, 25, 78, 237, 844, 2551, 7941, 25802, 82080, 258039, 822737, 2628312, 8359547, 26575371, 84674430, 269778131, 858987274, 2735603656, 8714789361, 27760710006, 88426843547, 281688270586, 897368531679, 2858705033226, 9106890037086
OFFSET
1,1
COMMENTS
Column 4 of A298582.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) -12*a(n-2) +20*a(n-3) -40*a(n-4) +24*a(n-5) -16*a(n-6) +17*a(n-7) +2*a(n-8) -35*a(n-9) +888*a(n-10) -518*a(n-11) +561*a(n-12) -1985*a(n-13) +352*a(n-14) +1184*a(n-15) -4415*a(n-16) -15823*a(n-17) +10078*a(n-18) -11814*a(n-19) +28636*a(n-20) -71602*a(n-21) +67017*a(n-22) +175544*a(n-23) +129097*a(n-24) -164526*a(n-25) +276657*a(n-26) -168617*a(n-27) +1143099*a(n-28) -1552674*a(n-29) +183029*a(n-30) -466745*a(n-31) -5355615*a(n-32) +87992*a(n-33) -9421360*a(n-34) +9643950*a(n-35) +4769007*a(n-36) +6862457*a(n-37) +22507266*a(n-38) -8384886*a(n-39) +16582290*a(n-40) -19359234*a(n-41) -13421595*a(n-42) -5636826*a(n-43) -31188540*a(n-44) +13998224*a(n-45) -14107677*a(n-46) +3586120*a(n-47) +10261492*a(n-48) +10322871*a(n-49) +13248762*a(n-50) -4087995*a(n-51) +7159113*a(n-52) -7884344*a(n-53) +2366049*a(n-54) -3814248*a(n-55) +114894*a(n-56) -1477857*a(n-57) +200042*a(n-58) +388778*a(n-59) +143476*a(n-60) +165330*a(n-61) -89336*a(n-62) +21844*a(n-63) -12656*a(n-64) -1608*a(n-65) -736*a(n-66) +608*a(n-67) -64*a(n-68) for n>69
EXAMPLE
Some solutions for n=5
..0..1..1..0. .0..1..1..0. .0..1..1..0. .0..1..1..0
..1..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..0
..0..1..0..0. .0..0..1..0. .0..0..1..1. .1..1..0..0
..1..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..0
..0..1..1..0. .0..1..1..0. .0..1..1..0. .0..1..1..0
CROSSREFS
Cf. A298582.
Sequence in context: A263537 A101863 A297955 * A299570 A329630 A018628
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 22 2018
STATUS
approved