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A073513 Number of primes less than 10^n with initial digit 5. 0
1, 3, 17, 131, 1055, 8615, 72951, 633932, 5602768, 50193913, 454577490, 4153943134, 38243708524, 354330372215, 3300752009165, 30892997367352, 290332329192655, 2738477783884855, 25913537508233527 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

Thomas R. Nicely, Some Results of Computational Research in Prime Numbers

EXAMPLE

a(2)=3 because there are 3 primes up to 10^2 whose initial digit is 5 (namely 5, 53 and 59).

MATHEMATICA

f[n_] := f[n] = PrimePi[6*10^n] - PrimePi[5*10^n] + f[n - 1]; f[0] = 1; Table[ f[n], {n, 0, 13}]

CROSSREFS

Cf. A073509 to A073517, their sum is A006880.

Sequence in context: A199493 A089815 A006759 * A074524 A163684 A093986

Adjacent sequences:  A073510 A073511 A073512 * A073514 A073515 A073516

KEYWORD

base,hard,nonn

AUTHOR

Shyam Sunder Gupta (guptass(AT)rediffmail.com), Aug 14 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 29 2002

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Last modified February 16 10:32 EST 2012. Contains 205904 sequences.