A205417 Number of (n+1)X2 0..3 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock differing from the number in all its horizontal and vertical neighbors

256, 2768, 31216, 345008, 3855292, 42869296, 477932092, 5320759096, 59277447518, 660147565952, 7353260497347, 81897935985740, 912200639448047, 10160026458425994, 113163447362993509, 1260415842112508290

Offset

1,1

Comments

Column 1 of A205422

Links

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

Formula

Empirical: a(n) = 84*a(n-2) +324*a(n-3) +684*a(n-4) +5414*a(n-5) +18901*a(n-6) +36870*a(n-7) +143492*a(n-8) +343938*a(n-9) +40768*a(n-10) -150414*a(n-11) -99939*a(n-12) -3297696*a(n-13) -11120072*a(n-14) -8376488*a(n-15) +15197186*a(n-16) +31001606*a(n-17) -11675195*a(n-18) -49570054*a(n-19) +20905770*a(n-20) +96572572*a(n-21) +51717035*a(n-22) -40813940*a(n-23) -122930663*a(n-24) -87507398*a(n-25) -11807220*a(n-26) +108567704*a(n-27) +71407480*a(n-28) -29180852*a(n-29) -82190628*a(n-30) -102278180*a(n-31) -79512996*a(n-32) -41480968*a(n-33) +7295869*a(n-34) +34396086*a(n-35) +22214484*a(n-36) +11734912*a(n-37) +5189888*a(n-38) -11136*a(n-39) -1300224*a(n-40) -656384*a(n-41) -147456*a(n-42) -16384*a(n-43) for n>44

Example

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

Crossrefs

Sequence in context: A236319 A236315 A205422 * A236127 A236124 A236949

Adjacent sequences: A205414 A205415 A205416 * A205418 A205419 A205420

Keyword

nonn

Author

R. H. Hardin Jan 27 2012

Status

approved