A280362 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal and vertical neighbors and with new values introduced in order 0 sequentially upwards.
1, 2, 2, 4, 9, 4, 11, 50, 50, 11, 30, 285, 571, 285, 30, 82, 1617, 6727, 6727, 1617, 82, 224, 9188, 78800, 164326, 78800, 9188, 224, 612, 52193, 924579, 3992071, 3992071, 924579, 52193, 612, 1672, 296511, 10844773, 97147710, 201054068, 97147710
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..2..1. .0..0..1..2. .0..1..2..0. .0..1..2..0. .0..1..0..2 ..0..2..1..0. .1..2..0..2. .0..2..1..2. .1..0..2..1. .0..2..1..2 ..1..0..0..1. .2..1..2..1. .1..1..2..1. .0..2..0..1. .2..1..2..1 ..0..2..2..1. .0..1..2..0. .0..0..1..0. .0..1..1..0. .2..0..2..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..97
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) +2*a(n-2) for n>4
k=2: a(n) = 6*a(n-1) -11*a(n-3) +4*a(n-4) for n>5
k=3: [order 12]
k=4: [order 44]
Comments