OFFSET
1,2
COMMENTS
Contains no multiples of 4 except 4, no terms == 0 or 8 (mod 9), and no multiples of 25. - Robert Israel, Oct 29 2024
LINKS
Patrick De Geest, Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n
Eric Weisstein's World of Mathematics, Consecutive Number Sequences
MAPLE
filter:= n -> numtheory:-issqrfree(parse(cat($1..n))):
select(filter, [$1..50]); # Robert Israel, Oct 29 2024
CROSSREFS
KEYWORD
nonn,hard,base
AUTHOR
Patrick De Geest, Feb 15 1999
EXTENSIONS
More terms from Sean A. Irvine, Jun 13 2021
Name edited by Robert Israel, Oct 29 2024
STATUS
approved