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A124477 Numbers k such that 24k+7 is a Mersenne prime (A000668). 26
0, 1, 5, 341, 5461, 21845, 89478485, 96076792050570581, 25790417485112089060398421, 6760803201217223474649083762005, 7089215977519551322153637654828504405 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Note that 2^m - 1 can be expressed as 24*k+7 whenever m is an odd integer >= 3. - Robert Israel, Jul 08 2014
LINKS
FORMULA
a(n) = (2^A000043(n+1)-8)/24. - Jeppe Stig Nielsen, Sep 17 2020
MAPLE
seq((numtheory:-mersenne([i+1])-7)/24, i=1..20); # Robert Israel, Jul 08 2014
PROG
(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
CROSSREFS
Sequence in context: A200002 A265921 A203684 * A059839 A300388 A269556
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 17 2006
EXTENSIONS
a(11) corrected by Michel Marcus, Jul 05 2014
STATUS
approved

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Last modified March 19 07:04 EDT 2024. Contains 370953 sequences. (Running on oeis4.)