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A268638 Number of n X 7 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totaling two exactly once. 1
576, 25272, 875592, 27906474, 849572724, 25093766490, 725187096504, 20612084839848, 578250487434612, 16051896344807322, 441734555450215308, 12067989070909055082, 327659984810446438932, 8849194102430720956704 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A268639.

LINKS

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

FORMULA

Empirical: a(n) = 110*a(n-1) -5243*a(n-2) +144650*a(n-3) -2610593*a(n-4) +33017408*a(n-5) -305811128*a(n-6) +2137462184*a(n-7) -11513372884*a(n-8) +48502300256*a(n-9) -161412354008*a(n-10) +427044616576*a(n-11) -901108804624*a(n-12) +1517344261024*a(n-13) -2035022988048*a(n-14) +2164824966496*a(n-15) -1815145078160*a(n-16) +1189730382208*a(n-17) -603502277248*a(n-18) +234173991424*a(n-19) -68574152448*a(n-20) +14906358784*a(n-21) -2352277504*a(n-22) +260550656*a(n-23) -19140608*a(n-24) +835584*a(n-25) -16384*a(n-26).

EXAMPLE

Some solutions for n=2

..1..2..1..0..1..0..1. .2..2..0..1..0..1..2. .1..1..0..1..0..1..0

..0..2..2..1..0..0..0. .1..2..1..2..1..2..1. .0..0..1..0..1..2..1

CROSSREFS

Cf. A268639.

Sequence in context: A330840 A226285 A282780 * A230522 A223301 A168660

Adjacent sequences:  A268635 A268636 A268637 * A268639 A268640 A268641

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 09 2016

STATUS

approved

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Last modified September 24 06:13 EDT 2021. Contains 347623 sequences. (Running on oeis4.)