OFFSET
1,2
COMMENTS
This sequence is a permutation of the squarefree numbers (A005117).
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, Colored logarithmic scatterplot of the first 100000 terms (where the color is function of A001221(a(n)))
Rémy Sigrist, PARI program for A338219
FORMULA
a(p) = p for any prime number p.
a(p) < a(n) for any prime number p and n > p.
EXAMPLE
For n = 1:
- we choose a(1) = 1.
For n = 2:
- a(2) must be divisible by a(1) = 1,
- we choose a(2) = 2.
For n = 3:
- a(3) must be divisible by a(1) = 1,
- we choose a(3) = 3.
For n = 4:
- a(4) must be divisible by a(1) = 1 and a(2) = 2,
- we choose a(4) = 6.
For n = 5:
- a(5) must be divisible by a(1) = 1,
- we choose a(5) = 5.
For n = 6:
- a(6) must be divisible by a(1) = 1, a(2) = 2 and a(3) = 3,
- we choose a(6) = 30.
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Rémy Sigrist, Jan 30 2021
STATUS
approved