This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A129542 #10 Nov 16 2019 11:34:57
%S A129542 1,10,99,820,7145,62161,546620,4880832,43998523,400227154,3669302718,
%T A129542 33866741579,314396207096,2933381107473,27490151938062,
%U A129542 258629969639330,2441659478947916,23122602510585989
%N A129542 Number of isolated primes < 10^n.
%C A129542 Isolated primes are primes that are not twin prime components. Define I(n) to be the number of isolated primes <= n. Given that Pi(n) -> infinity and I(n) -> infinity as n -> infinity, proving that pi(n) always grows by an ever so slight factor k>1 than I(n), then we will have infinity_Pi(n) - infinity_I(n) = infinity. So twin primes would be infinite in extent.
%H A129542 C. Hilliard, <a href="http://groups.yahoo.com/group/seqfun/files/Isolated%20primes/">Sum Isolated Primes</a>.
%H A129542 C. Hilliard, <a href="http://groups.yahoo.com/group/seqfun/message/38">Gcc code</a>. It took 7.5 hrs to compute a(12). It will take the Gcc program 3.2 days to compute a(13). For a(16) it will take about 8 years.
%H A129542 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 A129542 a(n) = A006880(n) - 2*A007508(n) + 1
%e A129542 The 10 isolated primes < 10^2 are 2,23,37,47,53,67,79,83,89,97 so 10 is the second entry in the table.
%o A129542 (PARI) countisoprimes(n) = \Count primes that are not twin prime components < 10^n { local(j,c,x); for(j=1,n, c=0; forprime(x=2,10^j, if(!isprime(x-2)&&!isprime(x+2),c++) ); print1(c",") ) }
%Y A129542 Cf. A006880, A007508.
%K A129542 hard,more,nonn
%O A129542 1,2
%A A129542 _Cino Hilliard_, Jun 08 2007
%E A129542 Edited by _Max Alekseyev_, Apr 27 2009