A199651 Number of nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.

14, 953, 59212, 3695683, 230693158, 14399942873, 898852775335, 56106912155198, 3502225890582058, 218610965399514236, 13645822881807986686, 851780155556891684028, 53168609887984551128913, 3318815376219262701965237

Offset: 1

Author

R. H. Hardin Nov 08 2011

Keywords

• nonn

Comments

Column 4 of A199655

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 60*a(n-1) +157*a(n-2) -186*a(n-3) -11412*a(n-4) -1614*a(n-5) +148235*a(n-6) -464921*a(n-7) -2730456*a(n-8) [phone]*a(n-9) [phone]*a(n-10) -103029710*a(n-11) -216889526*a(n-12) [phone]*a(n-13) [phone]*a(n-14) -529467638*a(n-15) -1980627795*a(n-16) -809314204*a(n-17) -566374358*a(n-18) [phone]*a(n-19) [phone]*a(n-20) [phone]*a(n-21) -240681242*a(n-22) -120679796*a(n-23) -174398008*a(n-24) -109877696*a(n-25) -6812544*a(n-26) +7732736*a(n-27) +5814784*a(n-28) +1263616*a(n-29) +155648*a(n-30) +98304*a(n-31) for n>32