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A099767
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Number of n-digit palindromes in base n.
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0
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1, 6, 12, 100, 180, 2058, 3584, 52488, 90000, 1610510, 2737152, 57921708, 97883968, 2392031250, 4026531840, 111612119056, 187339329792, 5808378560022, 9728000000000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,2
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FORMULA
| a(n) = (n - 1)*n^([(n + 1)/2] - 1) where [] is the greatest integer function
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EXAMPLE
| a(3) = 6 because there are 6 3-digit palindromes in base 3, namely 101, 111, 121, 202, 212, 222.
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MATHEMATICA
| (n - 1)*n^(Floor[(n + 1)/2] - 1) /. n -> Range[2, 20]
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CROSSREFS
| Sequence in context: A181597 A002898 A003613 * A191462 A080450 A144760
Adjacent sequences: A099764 A099765 A099766 * A099768 A099769 A099770
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KEYWORD
| easy,nonn
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AUTHOR
| Anonymous, Nov 11 2004
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