A240626 Number of nX3 0..3 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..3 introduced in row major order.

4, 109, 4369, 180480, 7462748, 308596193, 12761076882, 527696013254, 21821286982448, 902353910690193, 37314141073241635, 1543014450929326860, 63806737265585893957, 2638536352033321770102, 109108761540671975977499

Offset: 1

Author

R. H. Hardin, Apr 09 2014

Keywords

• nonn

Comments

Column 3 of A240629

Examples

			Some solutions for n=4
..0..1..1....0..1..2....0..1..2....0..0..1....0..1..0....0..0..1....0..1..1
..0..2..3....0..1..2....0..2..1....1..2..2....1..2..3....2..1..1....0..2..0
..3..3..1....1..3..1....1..3..0....2..0..1....2..0..3....3..0..1....3..2..0
..0..1..0....1..0..2....1..2..2....1..2..3....1..1..0....0..1..0....3..0..3
		

Links

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

Formula

Empirical: a(n) = 42*a(n-1) -20*a(n-2) -142*a(n-3) -5711*a(n-4) -3710*a(n-5) +80515*a(n-6) +372388*a(n-7) -2230154*a(n-8) +4624628*a(n-9) -9890649*a(n-10) [phone]*a(n-11) -3659227*a(n-12) -14748976*a(n-13) [phone]*a(n-14) -193948732*a(n-15) [phone]*a(n-16) -431237402*a(n-17) [phone]*a(n-18) [phone]*a(n-19) -536897174*a(n-20) [phone]*a(n-21) -566571559*a(n-22) [phone]*a(n-23) -508930511*a(n-24) [phone]*a(n-25) [phone]*a(n-26) -1224993018*a(n-27) [phone]*a(n-28) -819999594*a(n-29) -208353027*a(n-30) [phone]*a(n-31) [phone]*a(n-32) [phone]*a(n-33) [phone]*a(n-34) [phone]*a(n-35) -88064901*a(n-36) [phone]*a(n-37) [phone]*a(n-38) -80513676*a(n-39) -299431647*a(n-40) -419191038*a(n-41) -212845401*a(n-42) -113413446*a(n-43) -328430538*a(n-44) -226393866*a(n-45) -43046721*a(n-46)