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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. 235-253.

E. Fogels, On the average values of arithmetic functions, Proc. Cambridge Philos. Soc. 1941, 37: 358-372.

L. Marmet, First occurrences of squarefree gaps...

L. Marmet, First occurrences of square-free 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) 26:263-268.

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

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Last modified March 25 11:34 EDT 2017. Contains 284076 sequences.