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Search: id:A091707
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| A091707 |
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Number of primes less than 10^n having at least one digit 6. |
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+0
11
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| 0, 2, 32, 332, 3225, 31792, 309431, 2991216, 28863327, 278085918, 2677289604, 25769815303
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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a(1) = 0 because of the 4 primes less than 10^1, none have at least one digit 6.
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MATHEMATICA
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NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; c = 0; p = 1; Do[ While[ p = NextPrim[p]; p < 10^n, If[ Position[ IntegerDigits[p], 6] != {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (from Robert G. Wilson v Feb 02 2004).
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CROSSREFS
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a(n) + A091640(n) = A006880(n).
Cf. A091744, A091745, A091746, A091747, A046029, A091706, A091708, A091709, A091710.
Sequence in context: A158040 A079766 A053065 this_sequence A060868 A127697 A109772
Adjacent sequences: A091704 A091705 A091706 this_sequence A091708 A091709 A091710
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KEYWORD
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nonn,base
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Jan 30 2004
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 02 2004
3 more terms from Ryan Propper (rpropper(AT)stanford.edu), Aug 21 2005
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