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A065116 Numbers n such that sigma(n) +- tau(n) are primes. 1

%I

%S 8,162,512,32768,41472,3748322,5120000,6837602,8000000,35701250,

%T 75031250,78125000,91125000,907039232,10660336128,11911961250,

%U 21234895362,41265473762,55965865922,209642370242,835707290112,1148179179938,1821331173888,2097152000000

%N Numbers n such that sigma(n) +- tau(n) are primes.

%C Intersection of A064205 and A065061.

%H Donovan Johnson, <a href="/A065116/b065116.txt">Table of n, a(n) for n = 1..250</a>

%t Do[ds1 = DivisorSigma[1, n]; ds0 = DivisorSigma[0, n]; If[ PrimeQ[ds1 + ds0] && PrimeQ[ds1 - ds0], Print[n]], {n, 1, 10^7} ]

%Y Cf. A064205, A065061.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Nov 12 2001

%E a(10)-a(19) from _Donovan Johnson_, Jul 09 2010

%E a(20)-a(24) from _Donovan Johnson_, Aug 23 2013

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Last modified November 15 13:56 EST 2019. Contains 329149 sequences. (Running on oeis4.)