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A317607
Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 4, 5, 6, 7 or 8 king-move adjacent elements, with upper left element zero.
1
8, 28, 109, 472, 2639, 13134, 64593, 329236, 1675126, 8446443, 42786562, 217265141, 1100720836, 5579444003, 28303389818, 143512396002, 727722225397, 3690768784000, 18716882745820, 94919221030890, 481381697348861
OFFSET
1,1
COMMENTS
Column 4 of A317611.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) +3*a(n-2) +35*a(n-3) -452*a(n-4) -155*a(n-5) +533*a(n-6) +13741*a(n-7) +2499*a(n-8) -43056*a(n-9) -219748*a(n-10) +14737*a(n-11) +818297*a(n-12) +1930279*a(n-13) -836922*a(n-14) -7256644*a(n-15) -8463507*a(n-16) +9652762*a(n-17) +30042358*a(n-18) +8276678*a(n-19) -48653986*a(n-20) -38755062*a(n-21) +80978001*a(n-22) +118513732*a(n-23) -112226359*a(n-24) -359329590*a(n-25) -130184022*a(n-26) +437324109*a(n-27) +593626491*a(n-28) +97994618*a(n-29) -377404629*a(n-30) -383951462*a(n-31) -333976164*a(n-32) -305453122*a(n-33) +115673169*a(n-34) +705548344*a(n-35) +557947887*a(n-36) -228670118*a(n-37) -651497478*a(n-38) -180248988*a(n-39) +233509517*a(n-40) +173543506*a(n-41) +86940275*a(n-42) +167406414*a(n-43) +103248132*a(n-44) -56070870*a(n-45) -124187942*a(n-46) -92881708*a(n-47) -30334574*a(n-48) +1651971*a(n-49) +5732026*a(n-50) +11591790*a(n-51) +6626578*a(n-52) +4551578*a(n-53) +256283*a(n-54) +275556*a(n-55) +26060*a(n-56) +43200*a(n-57) +41074*a(n-58) -2902*a(n-59) +1072*a(n-60) -256*a(n-61) for n>63
EXAMPLE
Some solutions for n=5
..0..0..1..0. .0..0..0..0. .0..0..1..0. .0..0..0..0. .0..1..0..0
..1..0..0..0. .0..0..0..0. .0..0..0..0. .1..1..0..1. .0..0..0..0
..0..0..0..0. .0..1..1..0. .0..0..0..0. .1..1..1..0. .0..1..0..0
..0..0..0..0. .0..0..1..0. .0..1..1..0. .1..1..1..1. .1..0..0..0
..0..0..1..1. .0..1..0..0. .0..0..0..0. .0..0..1..1. .0..0..0..0
CROSSREFS
Cf. A317611.
Sequence in context: A220710 A260935 A289608 * A306545 A358285 A295914
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 01 2018
STATUS
approved