OFFSET
1,1
LINKS
Patrick De Geest, Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n
M. Fleuren, Factors and primes of Smarandache sequences.
Carlos Rivera, Puzzle 8. Primes by Listing, The Prime Puzzles & Problems Connection.
FORMULA
A046460(a(n)) = 3.
MAPLE
q:= n-> is(numtheory[bigomega](parse(cat($1..n)))=3):
select(q, [$1..35])[]; # Alois P. Heinz, Apr 10 2021
MATHEMATICA
Select[Range[100],
PrimeOmega@FromDigits@Flatten@IntegerDigits@Range@# == 3 &] (* Robert Price, Oct 11 2019 *)
CROSSREFS
KEYWORD
nonn,hard,base
AUTHOR
Patrick De Geest, Aug 15 1998
EXTENSIONS
a(10)-a(11) from Sean A. Irvine, Apr 10 2021
STATUS
approved