A209522 Number of nX3 0..7 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..7 introduced in row major order.

5, 57, 2027, 107693, 7700397, 687132348, 71519658191, 8190834795146, 990354435624550, 123286203872982432, 15583473550178836892, 1985385176761852694734, 253978177065210815069458

Offset: 1

Author

R. H. Hardin Mar 10 2012

Keywords

• nonn

Comments

Column 3 of A209527

Examples

			Some solutions for n=5
..0..0..0....0..0..1....0..0..0....0..0..0....0..0..1....0..1..0....0..0..0
..1..2..1....1..2..2....1..2..1....1..2..1....2..1..3....0..2..1....1..2..1
..0..0..1....0..0..1....3..2..3....0..0..0....3..1..0....0..1..0....0..0..0
..1..2..0....1..2..0....0..0..0....1..2..1....0..0..2....0..2..1....1..2..1
..0..0..1....2..0..1....1..2..1....3..2..3....1..2..1....1..1..0....3..1..0
		

Links

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

Formula

Empirical: a(n) = 272*a(n-1) -24648*a(n-2) +828436*a(n-3) +149527*a(n-4) -622108500*a(n-5) [phone]*a(n-6) -33558174264*a(n-7) -1578553176492*a(n-8) [phone]*a(n-9) -28667330106760*a(n-10) -594252767603616*a(n-11) +3792849444610432*a(n-12) -4923895161267584*a(n-13) -25653638667831936*a(n-14) +97101168572132352*a(n-15) -88244422976636928*a(n-16) -79190406866239488*a(n-17) +174755710679777280*a(n-18) -81018004244004864*a(n-19) +7489524376535040*a(n-20) for n>21