A302423 - OEIS

A302423

Number of nX4 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

5, 17, 21, 42, 148, 362, 879, 2447, 6306, 15905, 42221, 110418, 283913, 742439, 1940186, 5029913, 13102975, 34178122, 88873888, 231355589, 602826384, 1569061436, 4084569987, 10637783556, 27695951899, 72104297278, 187752963431

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OFFSET

1,1

COMMENTS

Column 4 of A302427.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +a(n-2) +11*a(n-3) -2*a(n-4) -3*a(n-5) -19*a(n-6) -5*a(n-7) -20*a(n-8) -60*a(n-9) -2*a(n-10) +10*a(n-11) +78*a(n-12) +30*a(n-13) +118*a(n-14) +191*a(n-15) +14*a(n-16) -14*a(n-17) -50*a(n-18) -165*a(n-20) -332*a(n-21) -84*a(n-22) -37*a(n-23) -86*a(n-24) -81*a(n-25) +40*a(n-26) +237*a(n-27) +110*a(n-28) +27*a(n-29) +62*a(n-30) +53*a(n-31) +27*a(n-32) -44*a(n-33) -26*a(n-34) -19*a(n-35) -21*a(n-36) -a(n-37) +2*a(n-38) +10*a(n-39) +a(n-40) -a(n-42) for n>43

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A302427.

Sequence in context: A211423 A211426 A224513 * A305478 A262620 A191210

Adjacent sequences: A302420 A302421 A302422 * A302424 A302425 A302426

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 07 2018

STATUS

approved