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A074549
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a(n) = 3^n + 4^n + 7^n.
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1
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3, 14, 74, 434, 2738, 18074, 122474, 842114, 5836898, 40635434, 283582874, 1981698194, 13858595858, 96957713594, 678496291274, 4748649600674, 33237268583618, 232647822996554, 1628482704807674, 11399171225541554
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internal format)
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OFFSET
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0,1
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LINKS
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FORMULA
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G.f.: 1/(1-3*x) + 1/(1-4*x) + 1/(1-7*x).
E.g.f.: exp(3*x) + exp(4*x) + exp(7*x). (End)
a(n) = 14*a(n-1) - 61*a(n-2) + 84*a(n-3).
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MATHEMATICA
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Table[3^n + 4^n + 7^n, {n, 0, 20}]
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PROG
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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