A240371 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4

3, 11, 21, 67, 155, 353, 998, 2256, 5639, 14624, 34169, 87040, 216484, 522354, 1320708, 3242252, 7968236, 19928605, 48905783, 121065218, 300575628, 739878493, 1834210821, 4538220894, 11200994822, 27751051195, 68588966317, 169541251841

Offset

1,1

Comments

Column 2 of A240376

Links

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

Formula

Empirical: a(n) = 3*a(n-2) +10*a(n-3) -3*a(n-4) -6*a(n-5) -3*a(n-6) +8*a(n-7) -7*a(n-8) -9*a(n-9) -4*a(n-10) +13*a(n-11) -14*a(n-12) +17*a(n-13) -a(n-15) for n>17

Example

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

Crossrefs

Sequence in context: A327607 A034185 A184053 * A158653 A129215 A139593

Adjacent sequences: A240368 A240369 A240370 * A240372 A240373 A240374

Keyword

nonn

Author

R. H. Hardin, Apr 04 2014

Status

approved