A209550 1/4 the number of (n+1)X6 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences

603, 16582, 425803, 11226644, 294738262, 7751834609, 203828058161, 5360172454106, 140957350430162, 3706813750652671, 97479558034241355, 2563460619809141337, 67412393287628933367, 1772771930441706450686

Offset

1,1

Comments

Column 5 of A209553

Links

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

Formula

Empirical: a(n) = 52*a(n-1) -856*a(n-2) +4014*a(n-3) +34244*a(n-4) -455004*a(n-5) +1232892*a(n-6) +6401520*a(n-7) -47507560*a(n-8) +64609279*a(n-9) +283015278*a(n-10) -991731422*a(n-11) -25138511*a(n-12) +4334710815*a(n-13) -4388934859*a(n-14) -8391654500*a(n-15) +15874524375*a(n-16) +6183586137*a(n-17) -26768058473*a(n-18) +3068141187*a(n-19) +25533122171*a(n-20) -9123208293*a(n-21) -14680808558*a(n-22) +7130958556*a(n-23) +5229264986*a(n-24) -2809641978*a(n-25) -1165852380*a(n-26) +598144917*a(n-27) +161163696*a(n-28) -66836588*a(n-29) -13174080*a(n-30) +3588829*a(n-31) +586993*a(n-32) -75654*a(n-33) -11622*a(n-34) +320*a(n-35) +76*a(n-36) +2*a(n-37)

Example

Some solutions for n=4
..0..3..0..1..0..3....0..2..0..2..0..2....1..0..1..0..1..2....3..2..1..0..3..0
..1..2..1..2..1..2....2..0..2..0..2..0....0..1..2..1..2..3....2..1..0..1..2..1
..2..3..2..1..0..1....0..2..0..2..0..2....1..2..3..2..3..2....3..0..1..2..3..0
..3..2..3..2..1..2....2..0..2..0..2..0....2..3..2..1..0..1....0..3..2..3..2..1
..2..3..2..1..0..3....0..2..0..2..0..2....3..2..1..2..1..0....3..0..1..2..3..2

Crossrefs

Sequence in context: A107256 A177685 A250907 * A151626 A031792 A020383

Adjacent sequences: A209547 A209548 A209549 * A209551 A209552 A209553

Keyword

nonn

Author

R. H. Hardin Mar 10 2012

Status

approved