A263799 - OEIS

A263799

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits, and rows and columns lexicographically nonincreasing

2, 2, 2, 3, 2, 3, 3, 3, 3, 3, 4, 3, 7, 3, 4, 4, 4, 7, 7, 4, 4, 5, 4, 14, 7, 14, 4, 5, 5, 5, 14, 17, 17, 14, 5, 5, 6, 5, 25, 18, 61, 18, 25, 5, 6, 6, 6, 25, 56, 130, 130, 56, 25, 6, 6, 7, 6, 41, 66, 494, 616, 494, 66, 41, 6, 7, 7, 7, 41, 218, 1435, 4991, 4991, 1435, 218, 41, 7, 7, 8, 7, 63, 272

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OFFSET

1,1

COMMENTS

Table starts

.2.2..3...3.....4.......4........5.........5.........6..........6.........7

.3.3..7...7....14......14.......25........25........41.........41........63

.3.3..7...7....17......18.......56........66.......218........272.......798

.4.4.14..17....61.....130......494......1435......4917......13962.....41366

.4.4.14..18...130.....616.....4991.....30130....185795....1022105...5241463

.5.5.25..56...494....4991....62904....760671...8468941...90476206.850301770

.5.5.25..66..1435...30130...760671..20141827.445862545.9910247963

.6.6.41.218..4917..185795..8468941.445862545

.6.6.41.272.13962.1022105.90476206

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..144

FORMULA

Empirical for column k:

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

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

k=3: a(n) = a(n-1) +3*a(n-2) -3*a(n-3) -3*a(n-4) +3*a(n-5) +a(n-6) -a(n-7)

k=4: [order 19]

k=5: [order 37]

k=6: [order 83]

EXAMPLE

Some solutions for n=5 k=4

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

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

CROSSREFS

Column 1 is A005578(n+1).

Sequence in context: A104307 A264029 A263873 * A299230 A182576 A368869

Adjacent sequences: A263796 A263797 A263798 * A263800 A263801 A263802

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Oct 26 2015

STATUS

approved