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Search: id:A073515
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| A073515 |
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Number of primes less than 10^n with initial digit 3. |
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+0
1
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| 1, 3, 19, 139, 1097, 8960, 75290, 651085, 5735086, 51247361, 463196868, 4225763390, 38851672813, 359541975662, 3345924530873, 31288310624754, 293820812588401, 2769490109678920, 26191046215879444, 248421640738371325
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Thomas R. Nicely, Some Results of Computational Research in Prime Numbers
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EXAMPLE
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a(2)=3 because there are 3 primes up to 10^2 whose initial digit is 3 (namely 3, 31 and 37).
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MATHEMATICA
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f[n_] := f[n] = PrimePi[4*10^n] - PrimePi[3*10^n] + f[n - 1]; f[0] = 1; Table[ f[n], {n, 0, 12}]
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CROSSREFS
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Cf. A073509 to A073517, their sum is A006880.
Sequence in context: A094662 A115750 A156894 this_sequence A074559 A027314 A025571
Adjacent sequences: A073512 A073513 A073514 this_sequence A073516 A073517 A073518
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KEYWORD
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hard,nonn
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AUTHOR
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Shyam Sunder Gupta (guptass(AT)rediffmail.com), Aug 14 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 29 2002
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