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A124477
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Numbers k such that 24k+7 is a Mersenne prime (A000668).
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26
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0, 1, 5, 341, 5461, 21845, 89478485, 96076792050570581, 25790417485112089060398421, 6760803201217223474649083762005, 7089215977519551322153637654828504405
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OFFSET
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1,3
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COMMENTS
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Note that 2^m - 1 can be expressed as 24*k+7 whenever m is an odd integer >= 3. - Robert Israel, Jul 08 2014
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LINKS
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FORMULA
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MAPLE
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seq((numtheory:-mersenne([i+1])-7)/24, i=1..20); # Robert Israel, Jul 08 2014
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PROG
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(PARI) for(n=0, 1e20, k=0; if(ispseudoprime(24*n+7), while(2^k-1 < 24*n+7, k++); if(24*n+7==2^k-1, print1(n, ", ")))) \\ Felix Fröhlich, Jul 04 2014
(PARI) lista(nn) = {vmps = readvec("b000043.txt"); if (nn== 0, nn = #vmps); for (i=1, nn, mpi = 2^vmps[i]-8; if ((mpi % 24) == 0, print1(mpi/24, ", ")); ); } \\ Michel Marcus, Jul 05 2014
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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