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A240154
Number of 2Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4
1
3, 5, 8, 19, 36, 57, 120, 218, 377, 758, 1366, 2451, 4815, 8678, 15839, 30594, 55356, 102004, 194522, 353711, 655297, 1238182, 2261878, 4202427, 7889648, 14469040, 26917836, 50315864, 92567160, 172279431, 321102231, 592194036, 1102055156
OFFSET
1,1
COMMENTS
Row 2 of A240153
LINKS
FORMULA
Empirical: a(n) = a(n-2) +8*a(n-3) -5*a(n-5) -18*a(n-6) +a(n-7) +10*a(n-8) +16*a(n-9) -5*a(n-10) -10*a(n-11) +a(n-12) +6*a(n-13) -2*a(n-14) -6*a(n-15) -a(n-16) +6*a(n-17) for n>19
EXAMPLE
Some solutions for n=4
..3..2..3..2....2..2..3..3....3..2..3..3....2..2..3..3....2..2..3..2
..3..2..1..1....0..0..2..1....3..1..2..2....0..2..1..1....0..2..1..1
CROSSREFS
Sequence in context: A184434 A196140 A336016 * A376785 A112656 A002366
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 02 2014
STATUS
approved