

A053806


Numbers where a gap begins in the sequence of squarefree numbers (A005117).


7



4, 8, 12, 16, 18, 20, 24, 27, 32, 36, 40, 44, 48, 52, 54, 56, 60, 63, 68, 72, 75, 80, 84, 88, 90, 92, 96, 98, 104, 108, 112, 116, 120, 124, 128, 132, 135, 140, 144, 147, 150, 152, 156, 160, 162, 164, 168, 171, 175, 180, 184, 188, 192, 196, 198, 200, 204, 207, 212
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,1


LINKS

Table of n, a(n) for n=0..58.
M. Filaseta and O. Trifonov, On Gaps between Squarefree Numbers. In Analytic Number Theory, Vol 85, 1990, Birkhauser, Basel, pp. 235253.
E. Fogels, On the average values of arithmetic functions, Proc. Cambridge Philos. Soc. 1941, 37: 358372.
L. Marmet, First occurrences of squarefree gaps...
L. Marmet, First occurrences of squarefree gaps and an algorithm for their computation, arXiv preprint arXiv:1210.3829 [math.NT], 2012.  From N. J. A. Sloane, Jan 01 2013
K. F. Roth, On the gaps between squarefree numbers, J. London Math. Soc. 1951 (2) 26:263268.


EXAMPLE

The first gap is at 4 and has length 1; the next starts at 8 and has length 2 (since neither 8 nor 9 are squarefree).


CROSSREFS

Cf. A005117, A053797, A045882, A051681, A013929.
Sequence in context: A274919 A196032 A130702 * A068306 A272405 A113645
Adjacent sequences: A053803 A053804 A053805 * A053807 A053808 A053809


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane, Apr 07 2000


STATUS

approved



