A241050 Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

3, 3, 4, 6, 8, 12, 13, 20, 28, 38, 53, 68, 96, 130, 178, 245, 330, 454, 617, 841, 1153, 1563, 2144, 2913, 3982, 5431, 7404, 10111, 13783, 18809, 25665, 34995, 47772, 65135, 88894, 121250, 165416, 225685, 307854, 420020, 572988, 781677, 1066446, 1454794

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-2) - a(n-4) + a(n-5) - a(n-7) + a(n-8) + a(n-11) for n>15.

Empirical g.f.: x*(3 + 3*x - 2*x^2 + 3*x^4 - 2*x^6 + x^7 + 4*x^8 + 3*x^9 - 2*x^11 - x^12 + x^13 + 2*x^14) / ((1 + x)*(1 - x - x^2 + x^3 - x^5 + x^6 - x^8 + x^9 - x^10)). - Colin Barker, Oct 29 2018

Example

All solutions for n=4:
..3..2....3..3....3..3....3..2....3..2....3..2
..2..0....2..0....2..2....2..0....2..0....2..0
..3..3....2..0....2..0....3..3....2..0....3..3
..3..2....2..0....2..0....2..2....2..0....2..0

Crossrefs

Column 2 of A241054.

Sequence in context: A240115 A196249 A241036 * A363237 A080013 A152949

Adjacent sequences: A241047 A241048 A241049 * A241051 A241052 A241053

Keyword

nonn

Author

R. H. Hardin, Apr 15 2014

Status

approved