A053845 - OEIS

%I #20 Apr 29 2024 09:09:07

%S 3,11,29,59,101,239,569,1061,1481,1721,4889,5351,6871,22549,23593,

%T 25801,29297,35569,38239,41023,71209,77137,87517,94057,105541,120349,

%U 122921,125509,128113,133387,138869,141677,156109,159073,165041,183707

%N Primes of form prime(1) + ... + prime(k) + 1.

%H Amiram Eldar, <a href="/A053845/b053845.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A007504(A089228(n)) + 1. - _Amiram Eldar_, Apr 29 2024

%e prime(1) + 1 = 2 + 1 = 3 (prime, thus a(1));

%e prime(1) + prime(2) + 1 = 2 + 3 + 1 = 6 (nonprime);

%e prime(1) + prime(2) + prime(3) + 1 = 2 + 3 + 5 + 1 = 11 (prime, thus a(2)); etc. - _Jon E. Schoenfield_, Jan 09 2015

%t p=1;lst={};Do[p+=Prime[n];If[PrimeQ[p],AppendTo[lst,p]],{n,7!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 14 2009 *)

%o (UBASIC) 10 x=x+1; 20 if x<>prmdiv(x) then 10; 30 y=x; 40 r=r+y; 50 if r=prmdiv(r) then print r;:p=p+1; 60 if p<100 then 10

%o (PARI) lista(nn) = {s = 1; for (n=1, nn, s += prime(n); if (isprime(s), print1(s, ", ")););} \\ _Michel Marcus_, Jan 10 2015

%Y Cf. A007504, A013918, A089228.

%K easy,nonn

%O 1,1

%A _Enoch Haga_, Mar 28 2000