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A046632
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Number of cubic residues mod 4^n.
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1
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1, 3, 10, 37, 147, 586, 2341, 9363, 37450, 149797, 599187, 2396746, 9586981, 38347923, 153391690, 613566757, 2454267027, 9817068106, 39268272421, 157073089683, 628292358730, 2513169434917, 10052677739667, 40210710958666
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: (-4x^3 - 2x^2 - x+1)/((1-4x)*(1-x^3)).
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MATHEMATICA
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LinearRecurrence[{4, 0, 1, -4}, {1, 3, 10, 37}, 40] (* Vincenzo Librandi, Jun 22 2012 *)
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PROG
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(Magma) I:=[1, 3, 10, 37]; [n le 4 select I[n] else 4*Self(n-1)+Self(n-3)-4*Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jun 22 2012
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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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STATUS
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approved
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