OFFSET
1,1
COMMENTS
4 is the only even term.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
EXAMPLE
377 = 13*29 and 13+29+1 is prime, so 377 is a term.
MATHEMATICA
With[{nn = 55}, Take[#, nn] &@ Union@ Flatten@ Table[Function[p, Map[Times @@ # &@ # &, #] &@ Select[Map[{p, #} &, Prime@ Range[PrimePi@ p]], PrimeQ[Total@ # + 1] &]]@ Prime@ n, {n, nn + 4}]] (* Michael De Vlieger, Aug 01 2017 *)
Select[Range[600], PrimeOmega[#]==2&&PrimeQ[Total[Times@@@ FactorInteger[ #]]+1]&] (* Harvey P. Dale, Sep 25 2019 *)
PROG
(Python)
from sympy import factorint, isprime
A290434_list = [n for n in range(2, 10**5) if sum(factorint(n).values()) == 2 and isprime(1+sum(factorint(n).keys())*(3-len(factorint(n))))]
(PARI) isok(n) = {if (bigomega(n) == 2, f = factor(n); if (#f~ == 1, isprime(2*f[1, 1]+1), isprime(vecsum(f[, 1]+1))); ); } \\ Michel Marcus, Aug 02 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Chai Wah Wu, Aug 01 2017
STATUS
approved