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Numbers n such that 1 plus the sum of the first n primes is divisible by n+1.
4

%I #16 Mar 15 2022 14:32:10

%S 2,6,224,486,734,50046,142834,170208,249654,316585342,374788042,

%T 2460457826,2803329304,6860334656,65397031524,78658228038

%N Numbers n such that 1 plus the sum of the first n primes is divisible by n+1.

%C a(17) > pi(4*10^12). - _Donovan Johnson_, Jul 02 2010

%t k = 0; s = 1; p = 2; lst = {}; While[k < 10^9, s = s + p; If[ Mod[s, ++k + 1] == 0, AppendTo[lst, k]; Print[{k, p}]]; p = NextPrime@ p]

%Y Cf. A153022, A045345, A128165, A000040, A007504, A111441.

%K nonn,more

%O 1,1

%A _Ctibor O. Zizka_, Mar 24 2009

%E a(6)-a(8) from _R. J. Mathar_, Mar 26 2009

%E a(9)-a(11) from _Donovan Johnson_, Nov 15 2009

%E a(12)-a(13) from _Ray Chandler_, May 31 2010

%E a(14)-a(16) from _Donovan Johnson_, Jul 02 2010