A240041 Number of nX2 0..3 arrays with no element equal to zero 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

2, 4, 10, 22, 50, 119, 276, 637, 1473, 3355, 7682, 17497, 39777, 90406, 205111, 465359, 1054871, 2390302, 5415591, 12265608, 27777095, 62895884, 142401878, 322392952, 729835421, 1652150714, 3739914222, 8465684665, 19162662378, 43375394510

Offset

1,1

Comments

Column 2 of A240046

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) -12*a(n-5) -46*a(n-6) -36*a(n-7) +12*a(n-8) +107*a(n-9) +87*a(n-10) +2*a(n-11) -145*a(n-12) -138*a(n-13) -48*a(n-14) +147*a(n-15) +185*a(n-16) +89*a(n-17) -94*a(n-18) -210*a(n-19) -111*a(n-20) +40*a(n-21) +176*a(n-22) +85*a(n-23) +30*a(n-24) -77*a(n-25) -47*a(n-26) -57*a(n-27) +14*a(n-29) +21*a(n-30) +14*a(n-31) -3*a(n-32) +2*a(n-33) -5*a(n-34) +a(n-35) +2*a(n-36) +a(n-37) -a(n-38) for n>40

Example

All solutions for n=3
..3..2....3..2....2..3....3..2....2..3....3..2....2..3....3..2....3..2....2..3
..2..0....1..0....3..0....1..0....1..0....1..0....3..0....2..0....2..0....3..0
..2..0....2..0....2..0....2..3....2..0....3..0....3..0....2..3....3..0....3..2

Crossrefs

Sequence in context: A275445 A075560 A078040 * A164990 A348009 A121285

Adjacent sequences: A240038 A240039 A240040 * A240042 A240043 A240044

Keyword

nonn

Author

R. H. Hardin, Mar 31 2014

Status

approved