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A134872
Product of n-th Mersenne prime and 2^n.
0
6, 28, 248, 2032, 262112, 8388544, 67108736, 549755813632, 1180591620717411302912, 633825300114114700748351601664, 332306998946228968225951765070084096, 696898287454081973172991196020261297057792
OFFSET
1,1
COMMENTS
a(1)= 6, the first perfect number. a(2)= 28, the second perfect number. a(3)=248, the dimensions of E_8.
FORMULA
a(n)=A000668(n) * 2^n.
EXAMPLE
a(3)=248 because the third Mersenne prime is 31, 2^3=8 and 31*8=248.
MATHEMATICA
Table[(2^MersennePrimeExponent[n]-1)2^n, {n, 12}] (* Harvey P. Dale, Mar 26 2023 *)
CROSSREFS
Cf. A061029. Powers of 2: A000079. Mersenne primes: A000668.
Sequence in context: A336565 A216413 A090898 * A281003 A049603 A333927
KEYWORD
nonn
AUTHOR
Omar E. Pol, Nov 25 2007
EXTENSIONS
Spelling corrected and n(7) added by Jason G. Wurtzel, Aug 22 2010
More terms from Harvey P. Dale, Mar 26 2023
STATUS
approved