OFFSET
1,2
COMMENTS
LINKS
FORMULA
a(1) = 1.
Empirically:
- a(n) = n iff n belongs to A046022,
- a(2 * k) = 2^k for any k > 0,
- a(p^2) = 2 * p for any prime p,
- a(p * q) = 3 * p for any pair of consecutive odd primes (p, q).
EXAMPLE
The first terms, alongside A020639(n), are:
n a(n) lpf(n)
-- ---- ------
1 1 1
2 2 2
3 3 3
4 4 2
5 5 5
6 8 2
7 7 7
8 16 2
9 6 3
10 32 2
11 11 11
12 64 2
13 13 13
14 128 2
15 9 3
16 256 2
17 17 17
18 512 2
19 19 19
20 1024 2
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jan 28 2018
STATUS
approved