A084995 - OEIS

%I #10 Feb 28 2022 19:07:39

%S 14,21,34,38,58,65,74,85,94,106,111,115,119,122,133,142,146,155,166,

%T 201,203,205,209,214,218,221,247,254,265,274,278,287,298,302,319,326,

%U 335,346,355,362,371,377,382,386,391,395,403,407,427,445,454,458,469,478,481,485

%N Numbers which can be written as the product of two different primes and the sum of digits is also prime.

%H Andrew Howroyd, <a href="/A084995/b084995.txt">Table of n, a(n) for n = 1..1000</a>

%F Intersection of A028834 and A006881. - _Andrew Howroyd_, Jan 05 2020

%e E.g., 14 = 7*2 and 1+4 = 5 is also prime.

%t Module[{nn=60},Select[Union[Times@@@Subsets[Prime[Range[nn]],{2}]],PrimeQ[ Total[ IntegerDigits[#]]]&&#<=2Prime[nn]&]] (* _Harvey P. Dale_, Feb 28 2022 *)

%o (PARI) is(n)={bigomega(n)==2 && !issquare(n) && isprime(sumdigits(n))}

%o select(is, [1..500]) \\ _Andrew Howroyd_, Jan 05 2020

%Y Cf. A006881, A028834, A108606.

%K nonn,base

%O 1,1

%A Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 30 2003

%E Terms a(14) and beyond from _Andrew Howroyd_, Jan 05 2020