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A304540
Number of nX4 0..1 arrays with every element unequal to 0, 1, 3, 4 or 6 king-move adjacent elements, with upper left element zero.
1
5, 17, 19, 70, 124, 328, 808, 2265, 6025, 17221, 50786, 150521, 450244, 1372877, 4203380, 12926183, 39917505, 123702709, 384029038, 1194002908, 3716951098, 11582357384, 36113695489, 112659146087, 351593620707, 1097602370102
OFFSET
1,1
COMMENTS
Column 4 of A304544.
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) -25*a(n-2) +49*a(n-3) -88*a(n-4) +119*a(n-5) -65*a(n-6) -152*a(n-7) +613*a(n-8) -1383*a(n-9) +2833*a(n-10) -3476*a(n-11) +1201*a(n-12) +2494*a(n-13) -6327*a(n-14) +5441*a(n-15) -2980*a(n-16) -13831*a(n-17) +51108*a(n-18) -53298*a(n-19) +43112*a(n-20) -28850*a(n-21) +9006*a(n-22) +15154*a(n-23) -86293*a(n-24) -173782*a(n-25) +97622*a(n-26) +351116*a(n-27) +771915*a(n-28) -1045721*a(n-29) +1602347*a(n-30) -1101590*a(n-31) -2933350*a(n-32) +2498594*a(n-33) -7951102*a(n-34) +7535499*a(n-35) -364183*a(n-36) +900547*a(n-37) +7133262*a(n-38) -9043595*a(n-39) +18595484*a(n-40) -12396661*a(n-41) +1055632*a(n-42) -5204833*a(n-43) -9274042*a(n-44) +4026235*a(n-45) -15979781*a(n-46) +18245073*a(n-47) +1039538*a(n-48) +9218669*a(n-49) -7253444*a(n-50) +738543*a(n-51) -21115*a(n-52) +1181762*a(n-53) -1020586*a(n-54) -1433205*a(n-55) -247891*a(n-56) +220792*a(n-57) +190608*a(n-58) -115798*a(n-59) +59808*a(n-60) +51680*a(n-61) +12336*a(n-62) -10128*a(n-63) +128*a(n-64) -3264*a(n-65) -384*a(n-66) +256*a(n-67) for n>68
EXAMPLE
Some solutions for n=5
..0..1..1..0. .0..0..1..1. .0..0..0..1. .0..0..0..0. .0..0..1..1
..1..1..1..1. .1..0..1..0. .1..0..0..0. .1..0..0..1. .0..1..1..1
..1..1..1..1. .1..1..1..0. .1..1..1..1. .1..1..1..1. .1..1..1..1
..1..1..1..1. .1..1..1..1. .1..1..0..1. .1..1..0..0. .1..1..1..1
..0..1..1..1. .0..1..1..1. .0..1..0..0. .0..1..0..1. .1..1..1..0
CROSSREFS
Cf. A304544.
Sequence in context: A171253 A226623 A171255 * A306125 A255901 A098333
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 14 2018
STATUS
approved