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A055553 Number of Carmichael numbers (A002997) less than 10^n. 61
0, 0, 1, 7, 16, 43, 105, 255, 646, 1547, 3605, 8241, 19279, 44706, 105212, 246683, 585355, 1401644, 3381806, 8220777, 20138200 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
There is still no agreement about the value of a(22), so a(22) has not been entered here yet. The latest email from Amiram Eldar (Jul 17 2024) that I received said: "There is a new version of Shallue and Webster's preprint (https://arxiv.org/abs/2401.14495) with a corrected value: 49679873 instead of 49483968. It is still different from Goutier's value (49679870), higher by merely 3. The check that I did on his list verified all of them, but could not rule out missing terms."
REFERENCES
Richard Pinch, Carmichael Numbers up to 10^20, ANTS 7.
LINKS
Claude Goutier, Compressed text file carm10e22.7z containing all the Carmichael numbers up to 10^22. [Local copy, with permission. This is a very large file.]
Romeo Meštrović, Generalizations of Carmichael numbers I, arXiv:1305.1867v1 [math.NT], May 4, 2013.
Richard G. E. Pinch, The Carmichael numbers up to 10^17, arXiv:math/0504119 [math.NT], 2005.
Richard G. E. Pinch, The Carmichael numbers up to 10^{17}, April 2005.
Richard G. E. Pinch, The Carmichael numbers up to 10^18, arXiv:math/0604376 [math.NT], 2006.
Richard G. E. Pinch, Carmichael numbers up to 10^18, April 2006.
Richard G. E. Pinch, ANTS 7 Posters.
Andrew Shallue and Jonathan Webster, Advances in Tabulating Carmichael Numbers, arXiv:2401.14495 [math.NT], 2024. [Appears to give an incorrect value for a(22). - N. J. A. Sloane, Apr 18 2024]
Eric Weisstein's World of Mathematics, Carmichael Number.
Eric Weisstein's World of Mathematics, Pseudoprime.
CROSSREFS
Cf. A002997.
Sequence in context: A020941 A318750 A024625 * A066009 A304013 A037241
KEYWORD
nonn,more,changed
AUTHOR
EXTENSIONS
Updates from Pinch's articles sent by Charles R Greathouse IV, Dec 04 2005, Jul 16 2006, May 29 2007
a(21) from Pinch's paper by Charles R Greathouse IV, Feb 01 2009
a(22) from Shallue and Webster (2024) added by Amiram Eldar, Feb 23 2024
a(22) = 49679870 reported by Claude Goutier on Dec 28 2022 (see links). - N. J. A. Sloane, Apr 18 2024
STATUS
approved

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Last modified July 20 11:19 EDT 2024. Contains 374445 sequences. (Running on oeis4.)