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A145712 Number of primes p in the range 9 < p <= prime(10^n) that have most significant and least significant decimal digit both equal to 9. 3
0, 0, 2, 245, 2053, 17518, 153645, 1362970, 12244431, 111153241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

a(3)=2 because out of the first 1000 primes, only two have first and last digits 9, 919 and 929.

CROSSREFS

Cf. A145709 A145710 A145711 A145713

Sequence in context: A013478 A049333 A140162 * A259141 A065664 A244926

Adjacent sequences:  A145709 A145710 A145711 * A145713 A145714 A145715

KEYWORD

hard,nonn,base

AUTHOR

Enoch Haga, Oct 16 2008

EXTENSIONS

Better definition from R. J. Mathar, Aug 04 2010

Edited and corrected by N. J. A. Sloane, Aug 16 2010

a(7)-a(10) from D. S. McNeil, Aug 29 2010

STATUS

approved

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Last modified September 21 15:13 EDT 2017. Contains 292300 sequences.