login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A065116 Numbers n such that sigma(n) +- tau(n) are primes. 1
8, 162, 512, 32768, 41472, 3748322, 5120000, 6837602, 8000000, 35701250, 75031250, 78125000, 91125000, 907039232, 10660336128, 11911961250, 21234895362, 41265473762, 55965865922, 209642370242, 835707290112, 1148179179938, 1821331173888, 2097152000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A064205 and A065061.

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..250

MATHEMATICA

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

CROSSREFS

Cf. A064205, A065061.

Sequence in context: A305524 A326099 A171461 * A240410 A061250 A183813

Adjacent sequences:  A065113 A065114 A065115 * A065117 A065118 A065119

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Nov 12 2001

EXTENSIONS

a(10)-a(19) from Donovan Johnson, Jul 09 2010

a(20)-a(24) from Donovan Johnson, Aug 23 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 21 14:20 EDT 2019. Contains 328301 sequences. (Running on oeis4.)