A318342 - OEIS

A318342

Number of nX7 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

64, 190, 344, 817, 3321, 16267, 86487, 476348, 2647555, 14797928, 82863837, 464502820, 2605038853, 14613251568, 81984567828, 459986291171, 2580903334169, 14481247495703, 81253869292071, 455915278972371, 2558145839414926

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OFFSET

1,1

COMMENTS

Column 7 of A318343.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) +15*a(n-2) -89*a(n-3) -165*a(n-4) +555*a(n-5) +1215*a(n-6) -1671*a(n-7) -5290*a(n-8) +1469*a(n-9) +13428*a(n-10) +5625*a(n-11) -17967*a(n-12) -19967*a(n-13) +3366*a(n-14) +22938*a(n-15) +28588*a(n-16) +12646*a(n-17) -41780*a(n-18) -75067*a(n-19) +9433*a(n-20) +89071*a(n-21) +52784*a(n-22) -43392*a(n-23) -74658*a(n-24) -40*a(n-25) +41248*a(n-26) +12244*a(n-27) -12324*a(n-28) -4868*a(n-29) +3028*a(n-30) +660*a(n-31) -1352*a(n-32) -152*a(n-33) +496*a(n-34) +32*a(n-35) -64*a(n-36) for n>41

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A318343.

Sequence in context: A078093 A209371 A317763 * A318074 A202332 A208636

Adjacent sequences: A318339 A318340 A318341 * A318343 A318344 A318345

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 24 2018

STATUS

approved