A239859 Number of 2 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

2, 3, 9, 12, 29, 63, 100, 215, 468, 785, 1654, 3515, 6048, 12676, 26381, 46460, 96810, 198286, 355994, 737992, 1493159, 2724777, 5619409, 11263131, 20836948, 42752798, 85081916, 159218104, 325067366, 643478067, 1215731399, 2470549558, 4871466920

Offset

1,1

Comments

Row 2 of A239858.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +7*a(n-3) -8*a(n-4) -7*a(n-5) +9*a(n-7) +10*a(n-8) -24*a(n-9) +5*a(n-10) +29*a(n-11) -18*a(n-12) -10*a(n-13) -10*a(n-14) +16*a(n-15) +12*a(n-16) -12*a(n-17) for n>21.

Example

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

Crossrefs

Cf. A239858.

Sequence in context: A057017 A330298 A330242 * A047162 A155929 A175206

Adjacent sequences: A239856 A239857 A239858 * A239860 A239861 A239862

Keyword

nonn

Author

R. H. Hardin, Mar 28 2014

Status

approved