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A139231
First differences of Mersenne primes A000668.
11
4, 24, 96, 8064, 122880, 393216, 2146959360, 2305843007066210304, 618970017336847128235868160, 162258657859193720701440560726016, 170141021201192402518323912137873817600
OFFSET
1,1
FORMULA
a(n) = A000668(n+1) - A000668(n).
EXAMPLE
a(1)=4 because A000668(1)=3 and A000668(2)=7 then 7-3 = 4.
MATHEMATICA
A000668 := Select[2^Range[1000] - 1, PrimeQ]; Table[A000668[[n + 1]] - A000668[[n]], {n, 1, 10}] (* G. C. Greubel, Oct 03 2017 *)
Differences[2^MersennePrimeExponent[Range[20]]-1] (* Harvey P. Dale, Mar 31 2022 *)
PROG
(PARI) a=0; b=0; forprime(p=1, 1e2, if(ispseudoprime(2^p-1) && a==0, a=2^p-1); if(ispseudoprime(2^p-1) && a!=0, b=2^p-1; if(a!=b, print1(b-a, ", ")); a=b)) \\ Felix Fröhlich, Aug 12 2014
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 18 2008
EXTENSIONS
a(8)-a(11) from Felix Fröhlich, Aug 12 2014
STATUS
approved