A080899 - OEIS

A080899

Primes p(k) such that every composite number between p(k) and p(k+1) has exactly three distinct prime factors.

29, 41, 59, 101, 137, 149, 179, 197, 227, 239, 269, 281, 311, 347, 521, 599, 617, 641, 643, 739, 809, 821, 827, 881, 1031, 1061, 1277, 1451, 1487, 1579, 1607, 1619, 1667, 1697, 1787, 1871, 1877, 1997, 2027, 2081, 2087, 2111, 2237, 2267, 2293, 2381

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Partition[Prime[Range[2, 360]], 2, 1], AllTrue[Range[First[#]+1, Last[#]-1], PrimeNu[#1] == 3 &] &][[;; , 1]] (* Amiram Eldar, Sep 14 2024 *)

PROG

(PARI) forprime(p=3, 3000, f=0; for(k=p+1, nextprime(p+1)-1, if(omega(k)!=3, f=1; break)); if(!f, print1(p", ")))

CROSSREFS

See A075583 for another version.

Sequence in context: A035789 A343478 A343479 * A216815 A157141 A107218

Adjacent sequences: A080896 A080897 A080898 * A080900 A080901 A080902

KEYWORD

nonn

AUTHOR

Ralf Stephan, Mar 30 2003

STATUS

approved