OFFSET
1,3
COMMENTS
Equivalently, these are the numbers with all digits, except possibly the leading digit, equal to zero or one in primorial base.
EXAMPLE
The first terms, alongside their primorial base representation, are:
n a(n) pbr(a(n))
-- ---- ---------
1 0 (0)
2 1 (1)
3 2 (1, 0)
4 3 (1, 1)
5 4 (2, 0)
6 5 (2, 1)
7 6 (1, 0, 0)
8 7 (1, 0, 1)
9 8 (1, 1, 0)
10 9 (1, 1, 1)
11 12 (2, 0, 0)
12 13 (2, 0, 1)
13 14 (2, 1, 0)
14 15 (2, 1, 1)
15 18 (3, 0, 0)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jun 01 2018
STATUS
approved