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A127634
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a(n) = 3^(n-1) - ceiling(n^n/n!).
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1
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0, 1, 4, 16, 54, 178, 565, 1770, 5493, 16927, 51901, 158533, 482802, 1466859, 4448104, 13467249, 40720970, 122994566, 371156622, 1119161662, 3372427789, 10156591942, 30573367574, 91993546765, 276703494365, 832023918335, 2501142914874, 7516883840470
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OFFSET
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1,3
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COMMENTS
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Theorem: 3^(n-1) > n^n/n! for n >= 3.
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REFERENCES
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D. S. Mitrinovic, Analytic Inequalities, Springer-Verlag, 1970; p. 193, 3.1.21.
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LINKS
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MAPLE
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MATHEMATICA
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PROG
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(PARI) a(n) = 3^(n-1) - ceil(n^n/n!); \\ Michel Marcus, Jul 06 2017
(Magma) [3^(n-1)-Ceiling(n^n/Factorial(n)): n in [1..30]]; // Vincenzo Librandi, Jul 06 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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