A129697 - OEIS

%I #14 Jul 02 2024 08:19:50

%S 2,577,51896,4009989,345281974,30126035380,2657646397769,

%T 238004015750349,21505022353019864,1960179022139638131,

%U 180020101551309284879,16639947666244921992434,1546703841471331792075283,144470014127904647017055666

%N Sum of isolated primes < 10^n.

%C Isolated primes are primes that are not twin prime members.

%H Cino Hilliard, <a href="http://groups.yahoo.com/group/seqfun/files/Isolated%20primes/">Sum Isolated Primes</a>. [broken link]

%H Cino Hilliard, <a href="http://groups.yahoo.com/group/seqfun/message/38">Gcc code</a>. [broken link]

%H Cino Hilliard, <a href="/A129542/a129542.txt">Sum of Isolated primes</a>, message 38 in seqfun Yahoo group, providing code for gcc (needs formatting to become compilable), Jun 5, 2007. [Cached copy]

%F a(n) = A046731(n) - A118552(n) + 5.

%e The sum of the isolated primes < 100 = 2+23+37+47+53+67+79+83+89+97 = 577, the second term of this sequence.

%o (PARI) isoprimes(n) = { local(j,s,x); for(j=1,n, s=0; forprime(x=2,10^j, if(!isprime(x-2)&&!isprime(x+2),s+=x) ); print1(s", ") ) }

%Y Cf. A007510, A046731, A118552, A129542.

%K nonn,hard,more

%O 1,1

%A _Cino Hilliard_, Jun 08 2007

%E a(13)-a(14) from _Amiram Eldar_, Jul 02 2024