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A181704 Numbers m=2^(t-1)*(2^t-5), where 2^t-5 is prime. 2

%I

%S 12,88,1888,32128,521728,8378368,34359083008,549753192448,

%T 2251799645913088,9223372026117357568,2361183241263023915008,

%U 2596148429267413634121263069790208,2722258935367507707522529418717050175488

%N Numbers m=2^(t-1)*(2^t-5), where 2^t-5 is prime.

%C All these numbers are in A181595 because their abundance is 4, a proper divisor of m.

%t Rest[2^(#-1) (2^#-5)&/@(Round[N[Log[#+5]/Log[2]]]&/@Select[Table[2^t-5,{t,120}],PrimeQ])] [From Harvey P. Dale, Dec. 16, 2010]

%Y Cf. A059608, A156560, A181595, A181701, A000396, A181703, A045769

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Nov 06 2010

%E 571728 replaced by 521728 - _R. J. Mathar_, Dec 05 2010

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Last modified April 20 15:38 EDT 2021. Contains 343135 sequences. (Running on oeis4.)