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A303080 Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1
1, 20, 29, 90, 304, 1054, 4182, 17369, 75377, 335199, 1511973, 6877743, 31436925, 144097153, 661586920, 3040460522, 13981091806, 64311876578, 295889956660, 1361516449806, 6265388048955, 28833190731421, 132693419071842 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A303084.

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -20*a(n-2) +40*a(n-3) -120*a(n-4) +154*a(n-5) -227*a(n-6) +511*a(n-7) +23*a(n-8) +913*a(n-9) -826*a(n-10) -2376*a(n-11) -4502*a(n-12) -920*a(n-13) +3818*a(n-14) +8855*a(n-15) -818*a(n-16) -403*a(n-17) +2092*a(n-18) +20390*a(n-19) +17737*a(n-20) +13494*a(n-21) +4257*a(n-22) +11150*a(n-23) +41175*a(n-24) +19200*a(n-25) -34770*a(n-26) -72210*a(n-27) -29661*a(n-28) +7521*a(n-29) +6424*a(n-30) -14914*a(n-31) -37578*a(n-32) -31048*a(n-33) +39954*a(n-34) +42548*a(n-35) -9756*a(n-36) -24760*a(n-37) -7244*a(n-38) +12262*a(n-39) +22816*a(n-40) +9539*a(n-41) -6968*a(n-42) -8366*a(n-43) +142*a(n-44) +5260*a(n-45) +1414*a(n-46) -1709*a(n-47) -1376*a(n-48) -1138*a(n-49) -624*a(n-50) +218*a(n-51) +300*a(n-52) +84*a(n-53) +36*a(n-54) +16*a(n-55) -16*a(n-56) for n>57

EXAMPLE

Some solutions for n=5

..0..0..0..1. .0..0..1..0. .0..1..1..0. .0..1..1..1. .0..0..0..1

..0..0..0..1. .0..0..1..0. .1..1..1..0. .1..1..1..0. .0..0..0..1

..0..1..0..1. .1..1..1..1. .0..1..1..0. .0..0..1..0. .0..0..0..0

..0..0..0..1. .0..1..0..0. .0..1..1..0. .0..0..1..1. .1..1..1..1

..0..0..0..0. .0..1..0..0. .1..1..1..0. .0..0..1..1. .1..1..1..0

CROSSREFS

Cf. A303084.

Sequence in context: A045207 A039286 A043889 * A113621 A166676 A125561

Adjacent sequences:  A303077 A303078 A303079 * A303081 A303082 A303083

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 18 2018

STATUS

approved

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Last modified April 11 16:42 EDT 2021. Contains 342888 sequences. (Running on oeis4.)