A153022 - OEIS

%I #13 Mar 16 2022 16:19:38

%S 6,10,150,238,56824,665460,18468766,193274008,635705422,790546908,

%T 33256634229,66874977806,68066767730

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

%C No further term <200000. [_R. J. Mathar_, Jan 17 2009]

%C a(11) > pi(10^11). [_Donovan Johnson_, Mar 10 2010]

%C a(14) > 118*10^9. - _Robert Price_, Apr 10 2013

%F {n: n+1 | A024525(n) }. [_R. J. Mathar_, Jan 17 2009]

%e 1 plus the sum of squares of the first 6 primes: (1 + 2^2 + 3^2 + ... + 13^2)/7 = 54, thus 6 is an element of the sequence.

%Y Cf. A111441, A045345, A140480

%K nonn,more

%O 1,1

%A _Ctibor O. Zizka_, Dec 16 2008

%E a(5) from _R. J. Mathar_, Jan 17 2009

%E a(6)-a(10) from _Donovan Johnson_, Mar 10 2010

%E a(11)-a(13) from _Robert Price_, Apr 10 2013