A055553 Number of Carmichael numbers (A002997) less than 10^n.

0, 0, 1, 7, 16, 43, 105, 255, 646, 1547, 3605, 8241, 19279, 44706, 105212, 246683, 585355, 1401644, 3381806, 8220777, 20138200, 49679870

Offset

1,4

References

Richard Pinch, Carmichael Numbers up to 10^20, ANTS 7.

Links

Table of n, a(n) for n=1..22.

Claude Goutier, Text file readme.text summarizing enumeration of Carmichael numbers up to 10^22.

Claude Goutier, Text file readme.text summarizing enumeration of Carmichael numbers up to 10^22. [Local copy, with permission]

Claude Goutier, Compressed text file carm10e22.gz containing all the Carmichael numbers up to 10^22.

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, The Carmichael numbers up to 10^21, May 2007; Proceedings of Conference on Algorithmic Number Theory 2007. - Charles R Greathouse IV, Feb 01 2009

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

Adjacent sequences: A055550 A055551 A055552 * A055554 A055555 A055556

Keyword

nonn,more

Author

Eric W. Weisstein

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