A206392 Number of n X 4 0..5 arrays with no element equal to another within a city block distance of two, and new values 0..5 introduced in row major order.

2, 25, 206, 1931, 16784, 151630, 1343560, 12046648, 107401612, 960610876, 8576723918, 76644197120, 684569775162, 6116039277778, 54633888067900, 488076198634430, 4360092827131800, 38950530867108738, 347957262094712236

Offset: 1

Author

R. H. Hardin, Feb 07 2012

Keywords

• nonn

Comments

Column 4 of A206396.

Examples

			Some solutions for n=4
..0..1..2..0....0..1..2..0....0..1..2..3....0..1..2..3....0..1..2..3
..2..3..4..5....2..3..4..5....4..3..0..5....4..3..0..4....3..4..5..0
..4..5..0..1....1..5..0..1....5..2..4..1....1..2..5..1....1..0..3..1
..0..1..2..3....3..4..2..3....0..1..5..3....0..4..3..2....2..5..4..2
		

Links

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

Crossrefs

Cf. A206396.

Formula

Empirical: a(n) = 14*a(n-1) -32*a(n-2) -281*a(n-3) +1738*a(n-4) -1728*a(n-5) -9767*a(n-6) +21963*a(n-7) -7410*a(n-8) +5706*a(n-9) -19704*a(n-10) +6028*a(n-11) +2512*a(n-12) -2176*a(n-13) for n>15.