

A275499


Number of n X 3 0..2 arrays with no element equal to any value at offset (2,1) (2,0) or (1,1) and new values introduced in order 0..2.


1



5, 54, 80, 136, 232, 516, 1168, 2660, 6024, 13716, 31168, 70868, 161176, 366452, 833360, 1894996, 4309160, 9799012, 22282576, 50670228, 115222840, 262014052, 595814224, 1354867540, 3080938312, 7005983220, 15931445856, 36227745252
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OFFSET

1,1


LINKS

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


FORMULA

Empirical: a(n) = 2*a(n1) + 2*a(n2)  2*a(n3)  4*a(n4) + 3*a(n5) + a(n6)  a(n7) for n>11.
Empirical g.f.: x*(5 + 44*x  38*x^2  122*x^3  72*x^4 + 141*x^5 + 97*x^6 + 11*x^7  106*x^8  4*x^9 + 36*x^10) / ((1  x)*(1  x  3*x^2  x^3 + 3*x^4  x^6)).  Colin Barker, Feb 04 2019


EXAMPLE

Some solutions for n=4:
..0..1..2. .0..0..0. .0..0..1. .0..0..0. .0..1..0. .0..1..0. .0..0..0
..1..2..2. .1..2..1. .2..1..1. .0..1..2. .1..1..2. .0..1..2. .1..2..2
..1..2..0. .2..2..1. .2..1..2. .1..2..2. .1..2..2. .1..2..2. .1..2..1
..2..0..0. .0..0..0. .1..0..2. .1..2..0. .0..0..0. .2..2..0. .0..0..1


CROSSREFS

Column 3 of A275504.
Sequence in context: A083757 A093674 A129664 * A275396 A275261 A208429
Adjacent sequences: A275496 A275497 A275498 * A275500 A275501 A275502


KEYWORD

nonn


AUTHOR

R. H. Hardin, Jul 30 2016


STATUS

approved



