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A218730
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a(n) = (27^n-1)/26.
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3
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0, 1, 28, 757, 20440, 551881, 14900788, 402321277, 10862674480, 293292210961, 7918889695948, 213810021790597, 5772870588346120, 155867505885345241, 4208422658904321508, 113627411790416680717, 3067940118341250379360, 82834383195213760242721
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OFFSET
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0,3
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COMMENTS
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Partial sums of powers of 27 (A009971); q-integers for q=27.
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LINKS
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FORMULA
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MATHEMATICA
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PROG
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(PARI) a(n)=27^n\26
(Magma) [n le 2 select n-1 else 28*Self(n-1)-27*Self(n-2): n in [1..20]]; // Vincenzo Librandi, Nov 07 2012
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CROSSREFS
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Cf. similar sequences of the form (k^n-1)/(k-1): A000225, A003462, A002450, A003463, A003464, A023000, A023001, A002452, A002275, A016123, A016125, A091030, A135519, A135518, A131865, A091045, A218721, A218722, A064108, A218724-A218734, A132469, A218736-A218753, A133853, A094028, A218723.
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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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