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A074534
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2^n + 4^n + 7^n.
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1
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3, 13, 69, 415, 2673, 17863, 121809, 840055, 5830593, 40616263, 283524849, 1981523095, 13858068513, 96956127463, 678491524689, 4748635284535, 33237225602433, 232647693987463, 1628482317649329, 11399170063804375
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..200
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FORMULA
| G.f.: 1/(1-2*x)+1/(1-4*x)+1/(1-7*x). E.g.f.: exp(2*x)+exp(4*x)+exp(7*x). [From Mohammad K. Azarian (azarian(AT)evansville.edu), Dec 27 2008]
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MATHEMATICA
| Table[2^n + 4^n + 7^n, {n, 0, 20}]
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PROG
| (MAGMA) [2^n + 4^n + 7^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011
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CROSSREFS
| Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
Sequence in context: A058307 A020107 A128079 * A153395 A067145 A088714
Adjacent sequences: A074531 A074532 A074533 * A074535 A074536 A074537
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KEYWORD
| easy,nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 23 2002
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