A187462 T(n,k)=Number of (n+1)X(n+1) 0..k arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric

6, 50, 26, 192, 1236, 144, 512, 13726, 89618, 1272, 1126, 84048, 5098224, 11684688, 15192, 2146, 325932, 100936174, 3387715318, 6112320620, 286392, 3760, 1118854, 1061948616, 216668424092, 19708386669940, 4871877392202, 7648032, 6112

Offset

1,1

Comments

Table starts

.........6................50................192..............512..........1126

........26..............1236..............13726............84048........325932

.......144.............89618............5098224........100936174....1061948616

......1272..........11684688.........3387715318.....216668424092.5212823523842

.....15192........6112320620.....19708386669940.7540469990506332

....286392.....4871877392202.150657364854061134

...7648032.17264863350746654

.314011868

Links

R. H. Hardin, Table of n, a(n) for n = 1..40

Example

Some k=3 solutions for 4X4
..0..2..2..0....0..2..3..3....0..2..2..3....0..2..2..2....0..2..2..0
..3..2..0..2....1..2..0..1....3..2..0..1....2..2..0..2....2..3..0..3
..2..0..1..2....3..0..2..3....2..0..3..3....2..0..1..1....2..0..1..0
..0..2..2..3....2..1..3..0....1..1..2..0....3..2..2..0....2..3..3..3

Crossrefs

Row 1 is A062801

Sequence in context: A187699 A212232 A187670 * A231270 A062801 A035290

Adjacent sequences: A187459 A187460 A187461 * A187463 A187464 A187465

Keyword

nonn,tabl

Author

R. H. Hardin Mar 10 2011

Status

approved