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A152923
a(n) = 2^(2*p-1)/8, where p is A000043(n).
3
1, 4, 64, 1024, 4194304, 1073741824, 17179869184, 288230376151711744, 332306998946228968225951765070086144, 23945242826029513411849172299223580994042798784118784, 1645504557321206042154969182557350504982735865633579863348609024
OFFSET
1,2
COMMENTS
Ultraperfect numbers (A139306), divided by 8.
LINKS
FORMULA
a(n) = A139306(n)/8 = A152921(n)/4 = A152922(n)/2.
MATHEMATICA
2^(2 * MersennePrimeExponent[Range[10]] - 4) (* Amiram Eldar, Oct 17 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Dec 15 2008
EXTENSIONS
a(9)-a(11) from Amiram Eldar, Oct 17 2024
STATUS
approved