A251390 T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock summing to 2 3 4 5 or 6

71, 571, 571, 4585, 12457, 4585, 36825, 271393, 271393, 36825, 295759, 5914339, 16036923, 5914339, 295759, 2375387, 128887759, 948010753, 948010753, 128887759, 2375387, 19077905, 2808783981, 56040713651, 152031391763, 56040713651

Offset

1,1

Comments

Table starts

.......71.........571............4585..............36825.................295759

......571.......12457..........271393............5914339..............128887759

.....4585......271393........16036923..........948010753............56040713651

....36825.....5914339.......948010753.......152031391763.........24381056748093

...295759...128887759.....56040713651.....24381056748093......10607219852841053

..2375387..2808783981...3312804237391...3909974244432939....4614802877342194801

.19077905.61210372853.195833921630923.627040122137369465.2007727783867224687619

Links

R. H. Hardin, Table of n, a(n) for n = 1..161

Formula

Empirical for column k:

k=1: a(n) = 8*a(n-1) +a(n-2) -6*a(n-3)

k=2: a(n) = 23*a(n-1) -21*a(n-2) -119*a(n-3) +66*a(n-4) +72*a(n-5) -32*a(n-6)

k=3: [order 15]

k=4: [order 40]

Example

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

Crossrefs

Sequence in context: A250975 A209960 A209953 * A251383 A180327 A201039

Adjacent sequences: A251387 A251388 A251389 * A251391 A251392 A251393

Keyword

nonn,tabl

Author

R. H. Hardin, Dec 01 2014

Status

approved