A129697 Sum of isolated primes < 10^n.
2, 577, 51896, 4009989, 345281974, 30126035380, 2657646397769, 238004015750349, 21505022353019864, 1960179022139638131, 180020101551309284879, 16639947666244921992434, 1546703841471331792075283, 144470014127904647017055666
Offset: 1
Examples
The sum of the isolated primes < 100 = 2+23+37+47+53+67+79+83+89+97 = 577, the second term of this sequence.
Links
- Cino Hilliard, Sum Isolated Primes. [broken link]
- Cino Hilliard, Gcc code. [broken link]
- Cino Hilliard, Sum of Isolated primes, message 38 in seqfun Yahoo group, providing code for gcc (needs formatting to become compilable), Jun 5, 2007. [Cached copy]
Programs
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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", ") ) }
Extensions
a(13)-a(14) from Amiram Eldar, Jul 02 2024
Comments