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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071179 n - (sum of prime factors of n) is prime. 1
4, 10, 12, 14, 15, 18, 20, 21, 24, 26, 28, 33, 35, 36, 38, 39, 44, 45, 48, 50, 51, 52, 56, 62, 63, 65, 69, 72, 75, 77, 80, 86, 91, 92, 93, 95, 98, 104, 108, 111, 112, 117, 122, 123, 129, 133, 135, 144, 146, 147, 148, 152, 159, 161, 162, 171, 172, 175, 176, 188, 189 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Prime factors taken without multiplicity. - Harvey P. Dale, Feb 04 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..2000

EXAMPLE

20 = 2^2.5 and 20-(2+5) = 13 is prime hence 20 is in the sequence

MATHEMATICA

Select[Range[200], PrimeQ[#-Total[Transpose[FactorInteger[#]][[1]]]]&] (* Harvey P. Dale, Feb 04 2014 *)

PROG

(PARI) for(n=1, 100, if(isprime(n-sumdiv(n, d, isprime(d)*d))==1, print1(n, ", ")))

CROSSREFS

Sequence in context: A092428 A170943 A102998 * A155475 A023693 A299634

Adjacent sequences:  A071176 A071177 A071178 * A071180 A071181 A071182

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Jun 10 2002

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 17 17:04 EDT 2018. Contains 313816 sequences. (Running on oeis4.)