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A129697 Sum of isolated primes < 10^n. 0
2, 577, 51896, 4009989, 345281974, 30126035380, 2657646397769, 238004015750349, 21505022353019864, 1960179022139638131, 180020101551309284879, 16639947666244921992434 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Also A046731(n) - A118552(n) + 5. This agrees with the program in the link up to n = 12.
LINKS
C. Hilliard, Sum Isolated Primes.
C. Hilliard, Gcc code.
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]
FORMULA
Isolated primes are primes that are not twin prime components.
EXAMPLE
The sum of the isolated primes < 100 = 2+23+37+47+53+67+79+83+89+97 = 577, the second entry in the table.
PROG
(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", ") ) }
CROSSREFS
Sequence in context: A134371 A306635 A212840 * A214911 A203770 A121850
KEYWORD
nonn,more,hard
AUTHOR
Cino Hilliard, Jun 08 2007
STATUS
approved

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Last modified March 19 01:57 EDT 2024. Contains 370952 sequences. (Running on oeis4.)