OFFSET
1,1
COMMENTS
a(5) has 4931 digits and is too large to include. - R. J. Mathar, May 30 2008
FORMULA
a(n) = 2^(2*A000668(n)-1)/2.
MATHEMATICA
a[n_] := 2^(2^(MersennePrimeExponent[n] + 1) - 4); Array[a, 4] (* Amiram Eldar, Jul 10 2025 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 13 2008
EXTENSIONS
One more term from R. J. Mathar, May 30 2008
STATUS
approved
