OFFSET
1,2
COMMENTS
The asymptotic density of this sequence is Product_{p prime} (1 - 1/(p^2-1)) = 0.53071182... (A065469). - Amiram Eldar, Sep 15 2024
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
The squarefree numbers are 1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 29, 30, ... which first increase by one after terms 1, 2, 4, 5, ...
MATHEMATICA
Join@@Position[Differences[Select[Range[100], SquareFreeQ[#]&]], 1]
PROG
(PARI) lista(kmax) = {my(is1 = 1, is2, c = 1); for(k = 2, kmax, is2 = issquarefree(k); if(is2, c++); if(is1 && is2, print1(c-1, ", ")); is1 = is2); } \\ Amiram Eldar, Sep 15 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 12 2024
STATUS
approved