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A091924
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Primes such that their decimal representations interpreted in base 11 are also prime.
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71
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2, 3, 5, 7, 29, 43, 61, 67, 89, 139, 193, 197, 199, 227, 263, 269, 281, 331, 353, 373, 379, 467, 571, 601, 607, 643, 733, 797, 809, 821, 827, 887, 919, 937, 1033, 1039, 1093, 1129, 1231, 1237, 1259, 1277, 1303, 1327, 1381, 1451, 1453, 1459, 1583
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OFFSET
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1,1
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COMMENTS
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See A090711 for a similar sequence whose definition works "in the opposite direction". - M. F. Hasler, Jan 03 2014
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LINKS
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FORMULA
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EXAMPLE
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A000040(10)=29 in base 11 is 2*11^1+9*11^0=31 prime, therefore 29 is a term.
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MAPLE
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filter:= proc(n) local L;
if not isprime(n) then return false fi;
L:= convert(n, base, 10);
isprime(add(L[i]*11^(i-1), i=1..nops(L)))
end proc:
select(filter, [2, seq(i, i=3..10000, 2)]); # Robert Israel, Jan 28 2018
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MATHEMATICA
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Select[Prime@ Range@ 250, PrimeQ@ FromDigits[IntegerDigits@ #, 11] &] (* Michael De Vlieger, Aug 29 2015 *)
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PROG
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(PARI) is(p, b=11)={my(d=digits(p)); isprime(vector(#d, i, b^(#d-i))*d~)&&isprime(p)} \\ M. F. Hasler, Jan 03 2014
(Magma) [n:n in PrimesUpTo(1600)| IsPrime(Seqint(Intseq(n), 11))]; // Marius A. Burtea, Jun 30 2019
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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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EXTENSIONS
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STATUS
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approved
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