A234191 Number of (n+2) X (1+2) 0..3 arrays with no increasing sequence of length 3 horizontally, diagonally downwards or antidiagonally downwards.

193264, 10370036, 552870656, 29472668500, 1570546543232, 83690878669284, 4459602725105968, 237636889981332820, 12662836664945997280, 674758128948756836356, 35955490268105707832016, 1915941756734205665615988

Offset

1,1

Comments

Column 1 of A234196.

Links

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

Formula

Empirical: a(n) = 56*a(n-1) -119*a(n-2) -1308*a(n-3) +23400*a(n-4) -1471264*a(n-5) +2773580*a(n-6) +41183056*a(n-7) -96018000*a(n-8) +164815744*a(n-9) -481311056*a(n-10) -1789740992*a(n-11) +2706969088*a(n-12) -1995040768*a(n-13) +114872384*a(n-14) +1679949056*a(n-15) -1477492736*a(n-16) +3012214784*a(n-17) -415727616*a(n-18) +599916544*a(n-19) -1973420032*a(n-20) +234881024*a(n-21) -167772160*a(n-22) +134217728*a(n-23).

Example

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

Crossrefs

Cf. A234196.

Sequence in context: A250689 A234196 A234197 * A183753 A236616 A258515

Adjacent sequences: A234188 A234189 A234190 * A234192 A234193 A234194

Keyword

nonn

Author

R. H. Hardin, Dec 21 2013

Status

approved