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A168420
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a(n) = 4 + 10*floor(n/2).
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1
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4, 14, 14, 24, 24, 34, 34, 44, 44, 54, 54, 64, 64, 74, 74, 84, 84, 94, 94, 104, 104, 114, 114, 124, 124, 134, 134, 144, 144, 154, 154, 164, 164, 174, 174, 184, 184, 194, 194, 204, 204, 214, 214, 224, 224, 234, 234, 244, 244, 254, 254, 264, 264, 274, 274, 284
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = 10*n - a(n-1) - 2, with n>1, a(1)=4.
E.g.f.: (1/2)*(5 - 8*exp(x) + (10*x + 3)*exp(2*x))*exp(-x). - G. C. Greubel, Jul 22 2016
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MATHEMATICA
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Table[4 + 10 Floor[n/2], {n, 70}] (* or *) CoefficientList[Series[(4 + 10 x - 4 x^2)/((1 + x) (x - 1)^2), {x, 0, 70}], x] (* Vincenzo Librandi, Sep 19 2013 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy,less
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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