A206506 Number of (n+1)X3 0..2 arrays with the number of clockwise edge increases in 2X2 subblocks nondecreasing rightwards and downwards

549, 7737, 93405, 1020756, 10505604, 103812645, 997160112, 9383642739, 86977382523, 797102746356, 7242496383288, 65374662519669, 587135801448765, 5252624153233296, 46849534683131463, 416887973306651277

Offset

1,1

Comments

Column 2 of A206512

Links

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

Formula

Empirical: a(n) = 20*a(n-1) -108*a(n-2) -116*a(n-3) +2081*a(n-4) -2052*a(n-5) -9023*a(n-6) +14684*a(n-7) +4103*a(n-8) -20511*a(n-9) +25590*a(n-10) -24138*a(n-11) -683*a(n-12) +30616*a(n-13) -32567*a(n-14) +8765*a(n-15) -850*a(n-16) +4935*a(n-17) +9392*a(n-18) -14485*a(n-19) +4202*a(n-20) +738*a(n-21) -1528*a(n-22) +1448*a(n-23) -608*a(n-24) +96*a(n-25)

Example

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

Crossrefs

Sequence in context: A249297 A245957 A352543 * A235829 A235834 A235585

Adjacent sequences: A206503 A206504 A206505 * A206507 A206508 A206509

Keyword

nonn

Author

R. H. Hardin Feb 08 2012

Status

approved