login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A230949
T(n,k)=Number of (n+3)X(k+3) 0..3 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero
9
6, 16, 16, 76, 34, 76, 314, 724, 724, 314, 1170, 1994, 8374, 1994, 1170, 4584, 28128, 85196, 85196, 28128, 4584, 18208, 76682, 854206, 606224, 854206, 76682, 18208, 71242, 1144652, 8838040, 22328204, 22328204, 8838040, 1144652, 71242, 278758
OFFSET
1,1
COMMENTS
Table starts
.....6......16........76.........314...........1170............4584
....16......34.......724........1994..........28128...........76682
....76.....724......8374.......85196.........854206.........8838040
...314....1994.....85196......606224.......22328204.......161835904
..1170...28128....854206....22328204......584293702.....15744800360
..4584...76682...8838040...161835904....15744800360....295706164414
.18208.1144652..91616256..6209914254...421312592376..29418861515276
.71242.3107746.944382122.44707108238.11212196319546.546918612768188
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 3*a(n-1) +14*a(n-3) +a(n-4) -a(n-5)
k=2: [order 16]
k=3: [order 30]
k=4: [order 70]
EXAMPLE
Some solutions for n=2 k=4
..0..x..3..x..3..x..3....0..x..2..x..1..x..1....0..x..0..x..3..x..1
..x..1..x..0..x..0..x....x..1..x..3..x..2..x....x..1..x..0..x..2..x
..2..x..2..x..1..x..3....2..x..0..x..1..x..3....2..x..2..x..1..x..1
..x..3..x..1..x..2..x....x..3..x..1..x..0..x....x..3..x..1..x..0..x
..2..x..0..x..0..x..1....2..x..2..x..0..x..3....2..x..0..x..3..x..3
CROSSREFS
Sequence in context: A301831 A183127 A222884 * A231023 A217186 A101239
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 01 2013
STATUS
approved