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A136582
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Sqrt(10)-primes: primes obtained by concatenating the first digits in the decimal expansion of sqrt(10).
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6
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OFFSET
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1,1
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COMMENTS
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n such that floor(sqrt(10^(2*n-1))) is prime (1, 2, 7, 18, 33, ...) are given in A136583.
This sequence is the list of prime terms in A017934.
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LINKS
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Table of n, a(n) for n=1..5.
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FORMULA
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a(n) = A017934(2*A136583(n)-1).
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PROG
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(Magma) // by Jason Kimberley, Aug 2011
for n in [1..499 by 2] do
f := Isqrt(10^n);
if IsPrime(f) then
printf "%o, ", f;
end if;
end for;
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CROSSREFS
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Cf. A010467, A017934, A017934, A131581, A132153, A136583, A175733, A175734.
Sequence in context: A282973 A005042 A317482 * A356516 A173649 A210648
Adjacent sequences: A136579 A136580 A136581 * A136583 A136584 A136585
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KEYWORD
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nonn,base
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AUTHOR
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Lekraj Beedassy, Jan 09 2008
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STATUS
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approved
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