login
A075583
Primes p such that the composite numbers between p and the next prime together contain exactly three distinct prime factors.
11
7, 29, 41, 59, 101, 137, 149, 179, 197, 227, 239, 269, 281, 311, 347, 521, 599, 617, 641, 809, 821, 827, 881, 1031, 1061, 1277, 1451, 1487, 1607, 1619, 1667, 1697, 1787, 1871, 1877, 1997, 2027, 2081, 2087, 2111, 2237, 2267, 2381, 2657, 2687, 2711, 2801, 2999
OFFSET
1,1
COMMENTS
p+2 is prime for all members p except 7. - David Wasserman, Jan 20 2005
LINKS
PROG
(Magma) a:=[]; for k in PrimesInInterval(2, 3000) 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 3 then Append(~a, k); end if; end for; a; // Marius A. Burtea, Sep 26 2019
CROSSREFS
See A080899 for another version.
Sequence in context: A156124 A155476 A166970 * A103603 A045465 A330723
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 26 2002
EXTENSIONS
More terms from David Wasserman, Jan 20 2005
STATUS
approved