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A251326 T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock having one or two 1s 9
10, 28, 28, 78, 116, 78, 220, 474, 474, 220, 618, 1982, 2804, 1982, 618, 1740, 8218, 17216, 17216, 8218, 1740, 4894, 34288, 104058, 157312, 104058, 34288, 4894, 13772, 142600, 636404, 1405454, 1405454, 636404, 142600, 13772, 38746, 594236, 3866110 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

.....10.......28........78.........220...........618............1740

.....28......116.......474........1982..........8218...........34288

.....78......474......2804.......17216........104058..........636404

....220.....1982.....17216......157312.......1405454........12770802

....618.....8218....104058.....1405454......18415674.......246926340

...1740....34288....636404....12770802.....246926340......4911447738

...4894...142600...3866110...114913804....3265612528.....96040080726

..13772...594236..23591052..1040818716...43595364706...1900083059348

..38746..2473510.143559096..9388632290..578517868594..37310824370952

.109020.10302766.875140808.84916233072.7707617770032.736337217038262

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..420

FORMULA

Empirical for column k:

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

k=2: a(n) = 3*a(n-1) +8*a(n-2) -13*a(n-3) -a(n-4) +2*a(n-5)

k=3: [order 10]

k=4: [order 19]

k=5: [order 36]

k=6: [order 71]

EXAMPLE

Some solutions for n=4 k=4

..0..1..0..1..1....1..0..0..0..1....1..0..0..0..1....0..0..0..0..0

..0..0..0..0..0....0..1..1..0..0....0..1..0..1..0....1..0..1..0..1

..1..0..1..0..1....1..0..0..1..0....0..1..0..0..0....0..0..1..0..1

..0..1..0..0..0....0..0..1..0..0....1..0..0..1..0....1..0..0..0..1

..1..0..1..1..1....1..1..0..1..0....0..1..1..0..1....0..0..1..0..0

CROSSREFS

Sequence in context: A196356 A196359 A184686 * A022422 A113962 A031105

Adjacent sequences:  A251323 A251324 A251325 * A251327 A251328 A251329

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Dec 01 2014

STATUS

approved

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Last modified February 24 13:05 EST 2020. Contains 332209 sequences. (Running on oeis4.)