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A034513
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1^n + 3^n + 9^n.
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86
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3, 13, 91, 757, 6643, 59293, 532171, 4785157, 43053283, 387440173, 3486843451, 31381236757, 282430067923, 2541867422653, 22876797237931, 205891146443557, 1853020231898563, 16677181828806733, 150094635684419611
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Also the sum of n-th powers of the divisors of 9.
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LINKS
| T. D. Noe, Table of n, a(n) for n=0..200
Index entries for sequences related to linear recurrences with constant coefficients, signature (13,-39,27).
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FORMULA
| G.f.: 1/(1-x)+1/(1-3*x)+1/(1-9*x). E.g.f.: e^x+e^(3*x)+e^(9*x). [From Mohammad K. Azarian (azarian(AT)evansville.edu), Dec 26 2008]
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MATHEMATICA
| Table[1^n + 3^n + 9^n, {n, 0, 20}]
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PROG
| (Other) sage: [sigma(9, n)for n in xrange(0, 19)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 04 2009]
(PARI) a(n)=1+3^n+9^n \\ Charles R Greathouse IV, Jun 10 2011
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CROSSREFS
| Cf. A001550, A001576, A001579, A074501 - A074580.
Sequence in context: A114477 A116434 A174290 * A098462 A183283 A006898
Adjacent sequences: A034510 A034511 A034512 * A034514 A034515 A034516
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KEYWORD
| easy,nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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