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A279979
Number of 3 X n 0..1 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
1
0, 9, 50, 221, 822, 2669, 8068, 23169, 64250, 173509, 459148, 1195219, 3069280, 7791834, 19587853, 48827241, 120818815, 297018329, 725970958, 1765237102, 4272245780, 10296018246, 24717636634, 59130589267, 140997069400, 335205034089, 794714054209, 1879307452216
OFFSET
1,2
COMMENTS
Row 3 of A279977.
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) -33*a(n-2) +60*a(n-3) -36*a(n-4) -78*a(n-5) +199*a(n-6) -165*a(n-7) -33*a(n-8) +200*a(n-9) -180*a(n-10) +66*a(n-11) +22*a(n-12) -78*a(n-13) +84*a(n-14) -40*a(n-15) -21*a(n-16) +15*a(n-17) -3*a(n-18) +18*a(n-19) +6*a(n-20) -4*a(n-21) -3*a(n-22) -3*a(n-23) -a(n-24) for n>30.
EXAMPLE
Some solutions for n=4:
..0..1..0..0. .0..1..0..0. .0..1..0..1. .0..0..0..1. .0..1..1..0
..0..1..0..1. .0..0..1..0. .1..1..1..1. .1..1..0..0. .0..0..1..1
..0..1..0..0. .1..1..0..1. .0..1..0..1. .1..0..1..0. .1..1..0..0
CROSSREFS
Cf. A279977.
Sequence in context: A280549 A084367 A006974 * A222993 A171480 A369906
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2016
STATUS
approved