A209549 1/4 the number of (n+1)X5 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences

191, 3051, 46515, 723636, 11226644, 174401424, 2708892873, 42079740150, 653660484008, 10153933128957, 157730759876805, 2450184099235301, 38061075490701271, 591239462480203821, 9184293917133748801

Offset

1,1

Comments

Column 4 of A209553

Links

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

Formula

Empirical: a(n) = 26*a(n-1) -177*a(n-2) +43*a(n-3) +3477*a(n-4) -10179*a(n-5) -6160*a(n-6) +62922*a(n-7) -59442*a(n-8) -82557*a(n-9) +141262*a(n-10) +24872*a(n-11) -112175*a(n-12) +5660*a(n-13) +41275*a(n-14) -1936*a(n-15) -7049*a(n-16) -319*a(n-17) +400*a(n-18) +56*a(n-19) +2*a(n-20)

Example

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

Crossrefs

Sequence in context: A264844 A061331 A177683 * A218595 A296580 A206860

Adjacent sequences: A209546 A209547 A209548 * A209550 A209551 A209552

Keyword

nonn

Author

R. H. Hardin Mar 10 2012

Status

approved