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A165505
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a(0)=1, a(1)=7, a(n) = 42*a(n-2) - a(n-1).
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2
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1, 7, 35, 259, 1211, 9667, 41195, 364819, 1365371, 13957027, 43388555, 542806579, 1279512731, 21518363587, 32221171115, 871550099539, 481739087291, 36123365093347, -15890323427125, 1533071657347699, -2200465241286949
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OFFSET
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0,2
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COMMENTS
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a(n)/a(n-1) tends to -7.
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LINKS
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FORMULA
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G.f.: (1+8*x)/(1+x-42*x^2).
a(n) = Sum_{k=0..n} A112555(n,k)*6^k.
E.g.f.: (14*exp(6*x) - exp(-7*x))/13. - G. C. Greubel, Oct 20 2018
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MAPLE
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MATHEMATICA
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LinearRecurrence[{-1, 42}, {1, 7}, 40] (* G. C. Greubel, Oct 20 2018 *)
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PROG
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(PARI) vector(40, n, n--; (14*6^n-(-7)^n)/13) \\ G. C. Greubel, Oct 20 2018
(Magma) [(14*6^n-(-7)^n)/13: n in [0..40]]; // G. C. Greubel, Oct 20 2018
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CROSSREFS
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KEYWORD
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easy,sign
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AUTHOR
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STATUS
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approved
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