OFFSET
1,1
EXAMPLE
84 has the prime factorization 2^2 *3^1 *7^1. So the distinct primes dividing 84 are 2,3 and 7. 3-2=1, a power of 2. And 7-3 = 4, also a power of 2. So 84 is included in this sequence.
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jun 30 2008
EXTENSIONS
Extended by Ray Chandler, Jun 22 2009
STATUS
approved