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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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FORMULA
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MATHEMATICA
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Module[{nn=50, sq10}, sq10=RealDigits[Sqrt[10], 10, nn][[1]]; Select[FromDigits/@Table[Take[sq10, n], {n, nn}], PrimeQ]] (* Harvey P. Dale, Dec 06 2023 *)
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PROG
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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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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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