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A302273
Number of n X 3 0..1 arrays with every element equal to 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
1, 7, 22, 79, 269, 942, 3401, 12283, 43006, 156939, 565249, 2007662, 7307653, 26305407, 94096702, 341521831, 1229036517, 4413205998, 15980067713, 57514505187, 206942767678, 748087603299, 2693270343273, 9700931065070
OFFSET
1,2
COMMENTS
Column 3 of A302278.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +5*a(n-2) +26*a(n-3) -66*a(n-4) -86*a(n-5) +79*a(n-6) +14*a(n-7) +13*a(n-8) -168*a(n-9) +250*a(n-10) +428*a(n-11) -232*a(n-12) -24*a(n-13) -160*a(n-14) +160*a(n-15) -256*a(n-16) -384*a(n-17) +256*a(n-18).
EXAMPLE
Some solutions for n=5:
0 0 1 0 1 0 0 0 0 0 1 1 0 0 1 0 1 0 0 1 1
1 1 0 0 0 1 0 1 0 0 0 1 1 1 0 1 0 1 0 0 1
1 1 1 0 1 1 0 0 1 1 1 1 0 0 0 0 1 0 1 1 1
1 0 0 0 0 0 1 0 0 1 1 0 1 0 0 1 0 1 0 1 1
0 1 1 0 1 1 0 1 0 0 0 1 0 1 1 1 1 1 1 0 0
CROSSREFS
Cf. A302278.
Sequence in context: A278767 A286186 A282035 * A151822 A302724 A305083
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 04 2018
STATUS
approved