OFFSET
1,2
COMMENTS
Essentially the same as A124033.
LINKS
Carlos Rivera, Puzzle 25. Composed primes (by G.L. Honaker, Jr.), The Prime Puzzles and Problems Connection. (A related puzzle.)
EXAMPLE
a(1) = 0, since any single-digit number with 1 prime factor is a prime!
MATHEMATICA
Table[Total[Table[If[CompositeQ[n]&&PrimeOmega[n]==x, 1, 0], {n, 10^(x-1), 10^x-1}]], {x, 8}] (* The program generates the first 8 terms of the sequence. *) (* Harvey P. Dale, Jun 19 2022 *)
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Patrick De Geest, Dec 15 1998
EXTENSIONS
One more term from Naohiro Nomoto, Jul 31 2001
a(9)-a(12) from Ray Chandler, Apr 12 2011
STATUS
approved