OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
Find primes followed by N with exactly three prime factors, without repetition.
EXAMPLE
a(0)=30 because 30 follows the prime 29 and has three factors 2, 3 and 5.
MAPLE
isA008864 := proc(n) if n -prevprime(n) = 1 then true ; else false ; fi ; end: isA033992 := proc(n) if nops(numtheory[factorset](n)) = 3 then true ; else false ; fi ; end: isA136152 := proc(n) isA008864(n) and isA033992(n) ; end: for n from 1 do p := ithprime(n) ; if isA136152(p+1) then print(p+1) ; fi ; od: # R. J. Mathar, Feb 20 2008
MATHEMATICA
Select[Prime[Range[110]]+1, PrimeNu[#]==3&] (* Harvey P. Dale, Apr 08 2012 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Dec 16 2007
EXTENSIONS
Edited by R. J. Mathar, Feb 20 2008
STATUS
approved