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Numbers n such that n is prime and is equal to the sum of the first k primes plus the product of the first k primes, for some k.
1

%I #7 Dec 19 2018 03:44:22

%S 11,227,30071,

%T 24647906487115793512432470614609487044327490547070674282967249490409801198254927547005559122946385681862066942903289,

%U 62797802135946735863734268232365323600796854989079318289826397214991489160762431714712874321823048719463864215556568570809157897364620234601356930764612312239892910549558645813243759770009793795858849126389709

%N Numbers n such that n is prime and is equal to the sum of the first k primes plus the product of the first k primes, for some k.

%C It is in the spirit of A096342 (only for 2 consecutive primes) and of A013918 (all primes but only the sum).

%C The corresponding values of k are 2, 4, 6, 60, 96, ... - _Amiram Eldar_, Dec 19 2018

%e 11=(2+3)+(2*3) and 11 is prime.

%e 227= (2+3+5+7)+(2*3*5*7) and 227 is prime.

%t tb = {};Do[pq = Plus @@ Prime[Range[1, k]] + Times @@ Prime[Range[1, k]]; If[PrimeQ[pq], AppendTo[tb, pq]], {k, 1, 200}]; tb

%Y Cf. A096342, A013918, A120851.

%K nonn

%O 1,1

%A _Carlos Alves_, Jul 08 2006