OFFSET
1,1
COMMENTS
The asymptotic density of this sequence is 0.142325864924778... (Mossinghoff et al., 2021).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Michael J. Mossinghoff, Tomás Oliveira e Silva, and Tim Trudgian, The distribution of k-free numbers, Mathematics of Computation, Vol. 90, No. 328 (2021), pp. 907-929; arXiv preprint, arXiv:1912.04972 [math.NT], 2019-2020.
EXAMPLE
7 is a term since 7 and 7 + 2 = 9 = 3^2 are cubefree, and 7 + 1 = 8 = 2^3 is not.
MATHEMATICA
cubeFreeQ[n_] := AllTrue[FactorInteger[n][[;; , 2]], # < 3 &]; Select[Range[400], Boole[cubeFreeQ /@ (# + {0, 1, 2})] == {1, 0, 1} &]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Nov 11 2021
STATUS
approved