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A303321 Number of nX4 0..1 arrays with every element equal to 0, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1
1, 8, 1, 2, 4, 3, 3, 10, 9, 10, 19, 29, 40, 65, 96, 148, 238, 356, 573, 865, 1381, 2136, 3369, 5245, 8248, 12925, 20251, 31889, 49995, 78599, 123579, 194464, 305630, 481471, 757704, 1193056, 1879551, 2961524, 4666170, 7355683, 11597513, 18284922 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A303325.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-2) +4*a(n-3) +2*a(n-4) -3*a(n-5) -6*a(n-6) -10*a(n-7) -16*a(n-8) -9*a(n-9) +11*a(n-10) +35*a(n-11) +39*a(n-12) +30*a(n-13) +13*a(n-14) -6*a(n-15) -38*a(n-16) -66*a(n-17) -80*a(n-18) -55*a(n-19) -14*a(n-20) +25*a(n-21) +49*a(n-22) +76*a(n-23) +90*a(n-24) +67*a(n-25) +16*a(n-26) -30*a(n-27) -46*a(n-28) -37*a(n-29) -49*a(n-30) -51*a(n-31) -12*a(n-32) +47*a(n-33) +62*a(n-34) +14*a(n-35) -16*a(n-36) -7*a(n-37) -8*a(n-38) -35*a(n-39) -48*a(n-40) -18*a(n-41) +19*a(n-42) +33*a(n-43) +23*a(n-44) +16*a(n-45) +12*a(n-46) +a(n-47) -6*a(n-48) -11*a(n-49) -8*a(n-50) -3*a(n-51) -a(n-52) +2*a(n-53) +a(n-54) +a(n-55) for n>57

EXAMPLE

All solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303325.

Sequence in context: A222217 A105473 A010518 * A077464 A088373 A154167

Adjacent sequences:  A303318 A303319 A303320 * A303322 A303323 A303324

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 21 2018

STATUS

approved

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Last modified August 4 07:32 EDT 2020. Contains 336201 sequences. (Running on oeis4.)