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A241429
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Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or one 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.
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1
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3, 5, 2, 3, 5, 6, 9, 10, 15, 21, 28, 38, 49, 67, 91, 122, 169, 226, 312, 423, 578, 791, 1075, 1471, 2003, 2732, 3731, 5080, 6941, 9457, 12908, 17609, 24015, 32776, 44699, 60991, 83206, 113499, 154866, 211239, 288211, 393168, 536370, 731761, 998249, 1361895
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OFFSET
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1,1
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4) + a(n-5) - 2*a(n-6) + a(n-7) + a(n-8) - 2*a(n-9) + 2*a(n-10) - a(n-11) for n>13.
Empirical g.f.: x*(3 - x - 8*x^2 + 5*x^3 + 6*x^4 - 8*x^5 + 2*x^6 + 4*x^7 - 5*x^8 + 3*x^9 - 6*x^11 + 4*x^12) / ((1 - x)*(1 - x - x^2 + x^3 - x^5 + x^6 - x^8 + x^9 - x^10)). - Colin Barker, Oct 30 2018
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EXAMPLE
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All solutions for n=4:
..3..3....2..2....3..3
..3..2....2..0....3..2
..2..0....2..0....2..0
..2..0....2..0....3..3
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CROSSREFS
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Column 2 of A241435.
Sequence in context: A306220 A057673 A279398 * A200109 A156060 A272476
Adjacent sequences: A241426 A241427 A241428 * A241430 A241431 A241432
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Apr 22 2014
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STATUS
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approved
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