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A300685 Number of nX4 0..1 arrays with every element equal to 1, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
2, 30, 272, 2229, 18225, 150558, 1242620, 10252421, 84598340, 698058898, 5760016131, 47528661500, 392181902406, 3236082261985, 26702477277848, 220335035126549, 1818090778973268, 15001945015288245, 123788293117652608 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A300689.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) +2*a(n-2) -67*a(n-3) -36*a(n-4) +254*a(n-5) +142*a(n-6) -334*a(n-7) -580*a(n-8) -250*a(n-9) +685*a(n-10) +1955*a(n-11) +908*a(n-12) -6774*a(n-13) -884*a(n-14) +21117*a(n-15) -3461*a(n-16) -41108*a(n-17) +344*a(n-18) +78230*a(n-19) +46859*a(n-20) -80680*a(n-21) -54337*a(n-22) +64685*a(n-23) -9411*a(n-24) -50611*a(n-25) +75723*a(n-26) +35614*a(n-27) -86921*a(n-28) -74180*a(n-29) -62395*a(n-30) -58582*a(n-31) -8539*a(n-32) +14149*a(n-33) +8353*a(n-34) +8215*a(n-35) +8235*a(n-36) +2955*a(n-37) -1996*a(n-38) -1572*a(n-39) -316*a(n-40) -97*a(n-41) +176*a(n-42) +69*a(n-43) -18*a(n-44) -2*a(n-45) -4*a(n-46) +a(n-47) for n>49

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A300689.

Sequence in context: A215237 A189103 A300423 * A300608 A301350 A036351

Adjacent sequences:  A300682 A300683 A300684 * A300686 A300687 A300688

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 11 2018

STATUS

approved

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Last modified January 17 10:21 EST 2022. Contains 350387 sequences. (Running on oeis4.)