A240401 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4

2, 5, 14, 24, 77, 182, 397, 1164, 2626, 6439, 17045, 39465, 100175, 251538, 602316, 1525842, 3756635, 9193532, 23052218, 56571408, 139814332, 347712483, 855278021, 2119654735, 5248572774, 12946151193, 32079791328, 79306295913, 195965663917

Offset

1,1

Comments

Column 2 of A240406

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)

Example

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

Crossrefs

Sequence in context: A220477 A049939 A296302 * A133375 A057295 A290414

Adjacent sequences: A240398 A240399 A240400 * A240402 A240403 A240404

Keyword

nonn

Author

R. H. Hardin, Apr 04 2014

Status

approved