A209964 Number of (n+1)X4 0..3 arrays containing all values 0..3 with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order

9, 665, 25435, 870686, 27112487, 795773818, 22419183624, 613401570788, 16424902481420, 432709421228995, 11258156191933508, 290080208368537797, 7417347951459937609, 188514123487930064371, 4767959508783108762389

Offset

1,1

Comments

Column 3 of A209969

Links

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

Formula

Empirical: a(n) = 66*a(n-1) -1487*a(n-2) +11648*a(n-3) +14141*a(n-4) -454021*a(n-5) +667500*a(n-6) +5458068*a(n-7) -11933206*a(n-8) -23623289*a(n-9) +65454499*a(n-10) +26595728*a(n-11) -134617798*a(n-12) +33919512*a(n-13) +79370592*a(n-14) -38830848*a(n-15) -7503360*a(n-16) +6127616*a(n-17) -655360*a(n-18)

Example

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

Crossrefs

Sequence in context: A221133 A015007 A054327 * A287937 A372184 A053973

Adjacent sequences: A209961 A209962 A209963 * A209965 A209966 A209967

Keyword

nonn

Author

R. H. Hardin Mar 16 2012

Status

approved