OFFSET
1,2
COMMENTS
How often is one of k or k+1 a prime for any solution k?
FORMULA
Let npf(k) be the number of factors of k; for 36, npf(36)=4 since 36=2*2*3*3. The sequence lists numbers k such that npf(k) + npf(k+1) = npf(2k+1).
EXAMPLE
For k=58, 58 + 59 = 117, npf(58) + npf(59) = 2 + 1 = 3 = npf(117), so 58 is a term.
MAPLE
A001222 := proc(n) numtheory[bigomega](n) ; end:
for n from 1 to 10000 do if isA159302(n) then printf("%d, ", n) ; fi; od:
# R. J. Mathar, Apr 10 2009
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
J. M. Bergot, Apr 09 2009
EXTENSIONS
Corrected and extended by R. J. Mathar, Apr 10 2009
STATUS
approved