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A241398
Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the 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
3, 5, 9, 23, 44, 93, 204, 368, 761, 1583, 2951, 6056, 12244, 23588, 47945, 95715, 187731, 378531, 752679, 1489014, 2986657, 5934705, 11787915, 23567455, 46847503, 93218990, 186017656, 369978815, 736728537, 1468604461, 2922396725, 5820645191
OFFSET
1,1
COMMENTS
Row 2 of A241397
LINKS
FORMULA
Empirical: a(n) = 2*a(n-2) +8*a(n-3) -a(n-4) -10*a(n-5) -18*a(n-6) +8*a(n-7) +20*a(n-8) +20*a(n-9) -24*a(n-10) -22*a(n-11) -a(n-12) +32*a(n-13) +8*a(n-14) -3*a(n-15) -12*a(n-16) +4*a(n-17) -5*a(n-18) -4*a(n-20) -3*a(n-21) +2*a(n-22) for n>23
EXAMPLE
Some solutions for n=4
..3..2..2..2....2..3..2..2....3..2..3..2....2..3..3..2....3..2..3..3
..2..0..1..0....2..1..0..0....2..1..1..2....2..1..1..2....1..2..1..2
CROSSREFS
Sequence in context: A147038 A146275 A089636 * A373897 A262483 A083366
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 20 2014
STATUS
approved