OFFSET
1,3
COMMENTS
The number of squarefree integers less than 10^n is 0, 6, 61, 608, 6083, 60794, 607926, 6079291, 60792694, 607927124, ... (see A053462).
LINKS
Bernd C. Kellner and Jonathan Sondow, Power-Sum Denominators, Amer. Math. Monthly, 124 (2017), 695-709; arXiv:1705.03857 [math.NT], 2017.
Bernd C. Kellner and Jonathan Sondow, On Carmichael and polygonal numbers, Bernoulli polynomials, and sums of base-p digits, #A52 Integers 21 (2021), 21 pp.; arXiv:1902.10672 [math.NT], 2019.
EXAMPLE
There are two terms of A324315 less than 10^3, namely, 231 and 561, so a(3) = 2.
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Bernd C. Kellner and Jonathan Sondow, Feb 23 2019
STATUS
approved