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A206272 Number of (n+1) X 4 0..2 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. 1
1233, 3168, 12429, 39306, 133866, 437340, 1528920, 4972464, 17378730, 56812524, 197823117, 647998686, 2252305758, 7394389266, 25660071480, 84368598492, 292322882925, 962789033730, 3330544867176, 10985542604052, 37947971462754 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A206277.

LINKS

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

FORMULA

Empirical: a(n) = 12*a(n-2) +22*a(n-4) +2*a(n-5) -340*a(n-6) +44*a(n-7) -30*a(n-8) +302*a(n-9) -3011*a(n-10) +198*a(n-11) +10251*a(n-12) -5274*a(n-13) +71024*a(n-14) -31264*a(n-15) -65095*a(n-16) +356*a(n-17) -100260*a(n-18) -55796*a(n-19) +285507*a(n-20) -129166*a(n-21) -253871*a(n-22) +145844*a(n-23) -497761*a(n-24) -139938*a(n-25) +558865*a(n-26) -259172*a(n-27) +120937*a(n-28) -90988*a(n-29) -849840*a(n-30) -208948*a(n-31) -309854*a(n-32) +4632*a(n-33) +119043*a(n-34) +74848*a(n-35) +43437*a(n-36) +90324*a(n-37) +60444*a(n-38) +22592*a(n-39) +12708*a(n-40) +4144*a(n-41) +8976*a(n-42) +1024*a(n-43) +1024*a(n-44) for n>49.

EXAMPLE

Some solutions for n=4:

..0..0..1..2....1..0..1..0....2..1..1..0....0..2..2..1....2..2..0..2

..1..1..2..2....2..0..0..2....2..0..0..2....2..2..2..1....2..1..2..2

..1..1..2..2....2..0..0..0....2..0..0..2....2..2..0..2....1..2..2..2

..2..2..0..0....1..2..0..0....0..1..1..0....0..0..1..1....2..2..2..0

..2..2..2..1....1..1..2..2....0..1..1..0....0..0..1..1....2..2..0..1

CROSSREFS

Sequence in context: A182721 A183881 A270540 * A064942 A101311 A055616

Adjacent sequences:  A206269 A206270 A206271 * A206273 A206274 A206275

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 05 2012

STATUS

approved

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Last modified October 25 09:51 EDT 2021. Contains 348239 sequences. (Running on oeis4.)