A304948 Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero.

1, 13, 21, 26, 70, 139, 287, 625, 1484, 3197, 7321, 17097, 38454, 89084, 206798, 474945, 1101200, 2553611, 5907111, 13701807, 31776804, 73676950, 170939314, 396615800, 920204959, 2135416683, 4955594995, 11500595479, 26691033523

Offset

1,2

Comments

Column 4 of A304952.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 5*a(n-1) -6*a(n-2) +5*a(n-3) -31*a(n-4) +32*a(n-5) +16*a(n-6) +52*a(n-7) +14*a(n-8) -221*a(n-9) +22*a(n-10) -325*a(n-11) +843*a(n-12) -151*a(n-13) -2*a(n-14) -1461*a(n-15) +751*a(n-16) +3412*a(n-17) -361*a(n-18) -3042*a(n-19) -8060*a(n-20) +9742*a(n-21) +9624*a(n-22) +1688*a(n-23) -33552*a(n-24) -19227*a(n-25) +9268*a(n-26) +91049*a(n-27) +2002*a(n-28) -27904*a(n-29) -154203*a(n-30) +59878*a(n-31) +87740*a(n-32) +129471*a(n-33) -35874*a(n-34) -160951*a(n-35) -7952*a(n-36) +94438*a(n-37) -180117*a(n-38) -197253*a(n-39) +307576*a(n-40) +368311*a(n-41) +98137*a(n-42) -558579*a(n-43) -296247*a(n-44) +198138*a(n-45) +118173*a(n-46) -11709*a(n-47) +38946*a(n-48) +208940*a(n-49) +170100*a(n-50) -123979*a(n-51) -143507*a(n-52) -81592*a(n-53) +42843*a(n-54) -47336*a(n-55) -21652*a(n-56) +28063*a(n-57) +32007*a(n-58) +5652*a(n-59) +2431*a(n-60) +2882*a(n-61) -2062*a(n-62) +396*a(n-63) -4214*a(n-64) +1195*a(n-65) -943*a(n-66) +369*a(n-67) -93*a(n-68) +84*a(n-69) -16*a(n-70) for n>71

Example

Some solutions for n=5
..0..1..1..1. .0..0..0..0. .0..1..0..0. .0..0..0..1. .0..1..1..0
..1..0..0..0. .0..0..0..0. .1..0..1..1. .1..1..0..0. .1..1..0..1
..0..1..1..0. .0..0..0..0. .1..0..1..0. .1..0..1..0. .0..1..1..1
..0..1..0..1. .0..0..0..0. .0..1..0..0. .0..0..1..1. .1..1..0..1
..1..0..0..1. .1..1..1..1. .1..0..0..1. .1..0..1..0. .0..1..1..0

Crossrefs

Cf. A304952.

Sequence in context: A049745 A332512 A304006 * A087683 A195375 A128819

Adjacent sequences: A304945 A304946 A304947 * A304949 A304950 A304951

Keyword

nonn

Author

R. H. Hardin, May 22 2018

Status

approved