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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
EXAMPLE
a(3)=2 because out of the first 1000 primes, only two have first and last digits 9, 919 and 929.
CROSSREFS
Sequence in context: A013478 A049333 A140162 * A259141 A065664 A244926
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 March 29 06:57 EDT 2024. Contains 371265 sequences. (Running on oeis4.)