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A091705
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Number of primes less than 10^n having at least one digit 4.
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7
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0, 3, 32, 326, 3231, 31953, 310456, 3000349, 28922364, 278508004, 2680391313, 25793058269, 248228108241, 2389543008906
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OFFSET
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1,2
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LINKS
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EXAMPLE
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a(2) = 3 because of the 25 primes less than 10^2, 3 have at least one digit 4.
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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], 4] != {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (* Robert G. Wilson v, Feb 02 2004 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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