A275039 Number of 4Xn 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-2) or (-2,0) and new values introduced in order 0..2.

6, 54, 146, 570, 2185, 8273, 31495, 120845, 462819, 1770014, 6774047, 25932054, 99241078, 379774913, 1453487054, 5562892365, 21289984945, 81479806330, 311837664172, 1193456060092, 4567548672431, 17480762283012, 66901812670647

Offset

1,1

Comments

Row 4 of A275037.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +19*a(n-3) -9*a(n-4) -9*a(n-5) +87*a(n-6) -46*a(n-7) -84*a(n-8) +7*a(n-9) -59*a(n-10) -45*a(n-11) +31*a(n-12) +23*a(n-13) +4*a(n-14) -a(n-15) -a(n-16) +a(n-17) for n>19

Example

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

Crossrefs

Cf. A275037.

Sequence in context: A153333 A284858 A343982 * A195901 A260955 A072368

Adjacent sequences: A275036 A275037 A275038 * A275040 A275041 A275042

Keyword

nonn

Author

R. H. Hardin, Jul 14 2016

Status

approved