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A280482
Number of 3Xn 0..2 arrays with no element unequal 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, 30, 208, 997, 4070, 15441, 55149, 189470, 630973, 2051794, 6544747, 20548963, 63673137, 195096252, 592041835, 1781597453, 5321888489, 15793808706, 46599296619, 136773367915, 399552426209, 1162212024424, 3367443663003
OFFSET
1,2
COMMENTS
Row 3 of A280480.
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) -43*a(n-2) +45*a(n-3) +162*a(n-4) -534*a(n-5) +298*a(n-6) +1054*a(n-7) -1829*a(n-8) +47*a(n-9) +1985*a(n-10) -895*a(n-11) -308*a(n-12) -1748*a(n-13) +1696*a(n-14) +2932*a(n-15) -3512*a(n-16) -896*a(n-17) +720*a(n-18) +1776*a(n-19) +960*a(n-20) -2752*a(n-21) -256*a(n-22) +704*a(n-23) +640*a(n-24) +256*a(n-25) -512*a(n-26) for n>32
EXAMPLE
Some solutions for n=4
..0..1..1..1. .0..1..1..1. .0..0..1..0. .0..0..0..1. .0..0..1..1
..1..1..0..0. .1..0..0..0. .0..2..2..0. .2..2..2..2. .0..1..0..1
..0..0..2..2. .0..0..0..2. .2..2..0..0. .1..1..1..1. .1..2..1..1
CROSSREFS
Cf. A280480.
Sequence in context: A165016 A209796 A209789 * A371721 A203617 A181629
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2017
STATUS
approved