A198536 Number of 2n X 4 0..4 arrays with values 0..4 introduced in row major order and each element equal to an even number of horizontal and vertical neighbors.

404, 7937268, 163506788110, 3368739754955320, 69406373651979823710, 1429984226143212404754264, 29462062047551694076888833310, 607008863611669902737169765762040

Offset

1,1

Comments

Column 2 of A198538.

Links

R. H. Hardin, Table of n, a(n) for n = 1..142

Formula

Empirical: a(n) = 21092*a(n-1) -10151677*a(n-2) +1615488592*a(n-3) -100012996587*a(n-4) +3657934987820*a(n-5) -199109856057719*a(n-6) +11035156399508768*a(n-7) -386864139175024800*a(n-8) +4074211331329931264*a(n-9) +27502847510918746368*a(n-10) -584633432058829185024*a(n-11) +155716589412424286208*a(n-12) +27704839078255785934848*a(n-13) -67555504034237340712960*a(n-14) -521383121388940359106560*a(n-15) +2165438441332855701241856*a(n-16) +1920671303369098918887424*a(n-17) -21445602402910633696690176*a(n-18) +32886302391654339326246912*a(n-19) +4723519404374252060672*a(n-20) -34312714864530842122715136*a(n-21) +19342813113834066795298816*a(n-22).

Example

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

Crossrefs

Cf. A198538.

Sequence in context: A306308 A185638 A332140 * A337047 A169904 A267893

Adjacent sequences: A198533 A198534 A198535 * A198537 A198538 A198539

Keyword

nonn,more

Author

R. H. Hardin, Oct 26 2011

Status

approved