A109790 - OEIS

%I #17 Jul 06 2024 04:42:27

%S 1,3,5,7,9,15,19,33,47,49,51,55,63,73,97,105,117,119,131,165,189,195,

%T 223,229,243,245,253,257,263,273,277,291,295,297,329,331,357,367,371,

%U 389,391,395,397,399,445,487,497,551,577,603,605,637,641,643,683,685

%N Numbers k such that A083186(k) is prime.

%H Amiram Eldar, <a href="/A109790/b109790.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale)

%t Select[Range[2000], PrimeQ[Sum[Prime[Prime[i]], {i, 1, #}]] &] (* _Stefan Steinerberger_, Jun 23 2007 *)

%t Flatten[Position[Accumulate[Prime[Prime[Range[800]]]],_?PrimeQ]] (* _Harvey P. Dale_, Jun 24 2012 *)

%Y Cf. A006450, A083186, A126144.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Jun 11 2007

%E More terms from _Stefan Steinerberger_, Jun 23 2007