A205210 Number of (n+1)X4 0..2 arrays with the determinants of 2X2 subblocks nondecreasing rightwards and downwards

1970, 23578, 357812, 5500266, 82656765, 1236875696, 18436719991, 274894006610, 4096658765789, 61068503876736, 910323429981851, 13571411382199926, 202331869493821777, 3016631530479873716, 44976603254442047199

Offset

1,1

Comments

Column 3 of A205215

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 33*a(n-1) -310*a(n-2) -394*a(n-3) +21463*a(n-4) -100223*a(n-5) -82352*a(n-6) +1802520*a(n-7) -4216752*a(n-8) -1467504*a(n-9) +18558720*a(n-10) -25132032*a(n-11) +10616832*a(n-12) for n>19

Example

Some solutions for n=4
..2..1..1..0....1..2..2..0....1..0..2..0....2..1..0..2....1..1..1..2
..1..0..0..0....0..0..0..0....0..0..0..0....1..0..0..1....2..0..0..0
..2..0..1..2....2..2..2..0....1..1..0..1....1..0..0..2....2..0..1..0
..1..0..1..2....0..0..0..0....0..0..0..0....0..0..0..0....1..0..2..1
..2..0..1..2....1..0..2..0....2..1..0..0....0..1..2..0....2..0..1..2

Crossrefs

Sequence in context: A256738 A252012 A250804 * A183692 A206218 A255967

Adjacent sequences: A205207 A205208 A205209 * A205211 A205212 A205213

Keyword

nonn

Author

R. H. Hardin Jan 23 2012

Status

approved