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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
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 31 2014
STATUS
approved