A198904 Number of nX6 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.

51, 62004, 89793204, 130292546801, 189062985604305, 274342896958292170, 398089706066811447174, 577654521153750977585383, 838214957290859115489996817, 1216305402162613228248847610489

Offset: 1

Author

R. H. Hardin Oct 31 2011

Keywords

• nonn

Comments

Column 6 of A198906

Examples

			Some solutions with values 0 to 4 for n=4
..0..1..0..2..3..4....0..1..0..2..0..3....0..1..0..2..3..0....0..1..0..2..0..3
..1..0..1..0..2..1....1..0..1..0..3..2....1..0..1..0..4..3....1..0..1..0..3..0
..0..1..0..2..1..4....0..1..0..3..4..0....0..1..0..2..3..1....0..1..0..3..0..1
..1..0..1..4..2..0....1..0..1..2..1..4....1..0..1..0..2..0....1..0..1..4..1..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..100

Formula

Empirical: a(n) = 1941*a(n-1) -806387*a(n-2) [phone]*a(n-3) -14409929271*a(n-4) [phone]*a(n-5) -21816737058431*a(n-6) [phone]*a(n-7) +7343185920165785*a(n-8) -245567930834154099*a(n-9) +3173967512676632848*a(n-10) -15227320856420081570*a(n-11) -91185217544269175883*a(n-12) +1851754850894045611993*a(n-13) -13021262413927953929580*a(n-14) +53026970301996239080604*a(n-15) -137791962761820102384680*a(n-16) +234523646685947458039624*a(n-17) -259529910793881853229984*a(n-18) +179240545997964052307808*a(n-19) -69895831119161489802880*a(n-20) +11699525896373883270144*a(n-21)