A238997 - OEIS

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A238997

T(n,k)=Number of nXk 0..3 arrays with no element equal to two plus the sum of elements to its left or two plus the sum of the elements above it, modulo 4

3, 7, 7, 15, 41, 15, 31, 203, 203, 31, 63, 955, 2365, 955, 63, 127, 4393, 25601, 25601, 4393, 127, 255, 20015, 270671, 638779, 270671, 20015, 255, 511, 90841, 2827709, 15482441, 15482441, 2827709, 90841, 511, 1023, 411621, 29422487, 370847909

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Table starts

....3.......7.........15............31...............63..................127

....7......41........203...........955.............4393................20015

...15.....203.......2365.........25601...........270671..............2827709

...31.....955......25601........638779.........15482441............370847909

...63....4393.....270671......15482441........860394281..........47194836429

..127...20015....2827709.....370847909......47194836429........5929702056895

..255...90841...29422487....8839918663....2576820346901......741313154055591

..511..411621..305525459..210298050207..140374233864007....92478950275376419

.1023.1863915.3170576253.4998886061169.7641515368274447.11527212881627494067

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..180

FORMULA

Empirical for column k:

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

k=2: [order 9]

k=3: [order 35]

EXAMPLE

Some solutions for n=3 k=4

..3..3..1..3....1..0..1..1....3..3..1..3....0..1..1..3....0..1..1..1

..0..3..0..2....0..3..2..0....0..3..2..2....0..1..0..2....1..0..1..2

..3..2..0..1....1..2..2..2....0..3..2..2....0..3..2..0....0..1..2..2

CROSSREFS

Column 1 is A000225(n+1)

Sequence in context: A240422 A130003 A098581 * A240260 A240427 A239047

Adjacent sequences: A238994 A238995 A238996 * A238998 A238999 A239000

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 08 2014

STATUS

approved