OFFSET
1,1
COMMENTS
For very large n, the probability of a(n) not being a twin prime is extremely small, unless the twin primes conjecture is false. - Sam Alexander, Oct 20 2003
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
Between 31 and the next prime 37, there are 5 composite numbers whose prime divisors are respectively for 32: {2}, 33: {3,11}, 34: {2,17}, 35: {5,7} and 36: {2,3}; hence, these distinct prime divisors are {2,3,5,7,11,17}, the number of these distinct prime divisors is 6, so 31 is a term. - Bernard Schott, Sep 26 2019
MATHEMATICA
Select[Partition[Prime[Range[1250]], 2, 1], Length[Union[Flatten[ FactorInteger/@ Range[ #[[1]]+1, #[[2]]-1], 1][[All, 1]]]]==6&][[All, 1]] (* Harvey P. Dale, May 25 2020 *)
PROG
(Magma) a:=[]; for k in PrimesInInterval(2, 10000) do b:={}; for s in [k..NextPrime(k)-1] do if not IsPrime(s) then b:=b join Set(PrimeDivisors(s)); end if; end for; if #Set(b) eq 6 then Append(~a, k); end if; end for; a; // Marius A. Burtea, Sep 26 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 26 2002
EXTENSIONS
More terms from Sam Alexander, Oct 20 2003
STATUS
approved