A136012 Numbers n in any run of two or more numbers each having exactly two distinct prime divisors.

14, 15, 20, 21, 22, 33, 34, 35, 36, 38, 39, 40, 44, 45, 46, 50, 51, 52, 54, 55, 56, 57, 58, 62, 63, 68, 69, 74, 75, 76, 77, 85, 86, 87, 88, 91, 92, 93, 94, 95, 96, 98, 99, 100, 111, 112, 115, 116, 117, 118, 119, 122, 123, 124, 133, 134, 135, 136, 141, 142, 143, 144

Offset

1,1

Links

Table of n, a(n) for n=1..62.

Example

a(3) to a(5), 20 to 22, are a run of 3 consecutive numbers each having exactly 2 distinct prime divisors.

Crossrefs

Cf. A001221, A064709.

Sequence in context: A114962 A278979 A220671 * A038456 A346549 A075658

Adjacent sequences: A136009 A136010 A136011 * A136013 A136014 A136015

Keyword

easy,nonn

Author

Enoch Haga, Dec 09 2007

Extensions

Corrected and edited by R. J. Mathar, Dec 12 2007

Status

approved