login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Partial sums of Pillai primes (A063980).
0

%I #3 Mar 30 2012 18:40:50

%S 23,52,111,172,239,310,389,472,581,718,857,1006,1199,1426,1659,1898,

%T 2149,2406,2675,2946,3223,3516,3823,4134,4451,4810,5189,5572,5961,

%U 6358,6759,7178,7609,8058,8519,8982,9449,9928,10427,10930,11451,12008,12571

%N Partial sums of Pillai primes (A063980).

%C The values alternate between odd and even. The first prime partial sum of Pillai primes is a(5) = 23 + 29 + 59 + 61 + 67 = 239. The second prime partial sum is a(7) = 389. The next such primes are a(11) = 857 (= the 72nd Pillai prime), a(23) = 3823, a(25) = 4451, a(27) = 5189. The coincidence which prompted this sequence is that the 266th Pillai prime is a(23), the sum of the first 23 Pillai primes. Curiously, 23 is the smallest Pillai prime. What are the next such Pillai primes in the partial sum?

%F a(n) = SUM[i=i..n]A063980(i) = SUM[i=i..n] {p: p prime and there exists an integer m such that m!+1 is 0 mod p and p is not 1 mod m}.

%e a(1) = 23 because 23 is the first Pillai prime A063980(1). a(2) = 52 because 23+29 = 52 is the sum of the first two Pillai primes A063980(1)+A063980(2).

%K nonn

%O 1,1

%A _Jonathan Vos Post_, Jan 23 2010

%E More terms from _R. J. Mathar_, Jan 24 2010