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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A069346 Primes of the form n - Omega(n), where Omega(n) is the number of prime factors of n, A001222(n). 7
2, 5, 7, 13, 17, 19, 23, 31, 37, 41, 43, 47, 53, 67, 73, 83, 89, 103, 107, 109, 113, 127, 131, 139, 151, 157, 163, 167, 179, 181, 199, 211, 227, 233, 239, 241, 251, 257, 263, 281, 283, 293, 307, 311, 313, 317, 337, 347, 353, 359 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The representation is ambiguous, see A069347.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

a(10) = 41 = A069345(44) = 44-3 (as 44 = 2*2*11).

MATHEMATICA

Select[Table[n - PrimeOmega[n], {n, 1, 400}], PrimeQ] // Union (* Jean-Fran├žois Alcover, Jun 08 2013 *)

PROG

(PARI) is(n)=for(k=1, log(n)\log(2)+1, if(bigomega(n+k)==k, return(isprime(n)))); 0 \\ Charles R Greathouse IV, Dec 10 2013

CROSSREFS

Cf. A069348, A069356.

Sequence in context: A275284 A261123 A249330 * A023240 A291284 A023204

Adjacent sequences:  A069343 A069344 A069345 * A069347 A069348 A069349

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 18 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 15 10:46 EDT 2019. Contains 328026 sequences. (Running on oeis4.)