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A118263
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a(3n) = 2^n, a(3n+1) = 3^n, a(3n+2) = 4^n.
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1
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1, 1, 1, 2, 3, 4, 4, 9, 16, 8, 27, 64, 16, 81, 256, 32, 243, 1024, 64, 729, 4096, 128, 2187, 16384, 256, 6561, 65536, 512, 19683, 262144, 1024, 59049, 1048576, 2048, 177147, 4194304, 4096, 531441, 16777216, 8192, 1594323, 67108864, 16384, 4782969
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OFFSET
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0,4
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LINKS
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FORMULA
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a(n)= 9*a(n-3) -26*a(n-6) +24*a(n-9. G.f.: -(1+x+x^2-7*x^3-6*x^4-5*x^5+12*x^6+8*x^7+6*x^8)/ ((3*x^3-1) * (2*x^3-1) * (4*x^ 3-1)). [R. J. Mathar, Mar 01 2010]
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MATHEMATICA
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Table[{2^Floor[n/3], 3^Floor[n/3], 4^Floor[n/3]}[[Mod[n, 3] + 1]], {n, 0, 100}] (* Olivier Gérard, Sep 20 2007 *)
LinearRecurrence[{0, 0, 9, 0, 0, -26, 0, 0, 24}, {1, 1, 1, 2, 3, 4, 4, 9, 16}, 60] (* Harvey P. Dale, Jan 30 2021 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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