A274726 Number of nX6 0..2 arrays with no element equal to any value at offset (-1,-2) (-2,-1) or (-1,0) and new values introduced in order 0..2.

122, 1536, 5728, 66132, 771300, 8960464, 105328812, 1237030912, 14505195904, 170291855288, 1998101079148, 23450606174376, 275190816259724, 3229562907115528, 37899889658769384, 444774756528884068

Offset: 1

Author

R. H. Hardin, Jul 03 2016

Keywords

• nonn

Comments

Column 6 of A274728.

Examples

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

Links

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

Crossrefs

Cf. A274728.

Formula

Empirical: a(n) = 3*a(n-1) +78*a(n-2) +250*a(n-3) +558*a(n-4) -937*a(n-5) -4256*a(n-6) -7991*a(n-7) -3472*a(n-8) +31381*a(n-9) -11144*a(n-10) +42683*a(n-11) -198936*a(n-12) +231086*a(n-13) -131301*a(n-14) +70502*a(n-15) -27827*a(n-16) +159651*a(n-17) -217780*a(n-18) +120250*a(n-19) -55920*a(n-20) -17125*a(n-21) +26805*a(n-22) -25487*a(n-23) +30226*a(n-24) -15183*a(n-25) +5503*a(n-26) -1930*a(n-27) +371*a(n-28) -65*a(n-29) +8*a(n-30) for n>35