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A299711
Number of eleven-prime Carmichael numbers less than 10^n.
10
1, 49, 576, 5804, 42764, 262818, 1388714, 6529921
(list; graph; refs; listen; history; text; internal format)
OFFSET
17,2
LINKS
Table of n, a(n) for n=17..24.
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]
Richard Pinch, Tables relating to Carmichael numbers.
Andrew Shallue and Jonathan Webster, Algorithms for Carmichael numbers, arXiv:2506.09903 [math.NT], 2025-2026.
Index entries for sequences related to Carmichael numbers.
EXAMPLE
60977817398996785 = 5*7*17*19*23*37*53*73*79*89*233 is the only Carmichael number with eleven prime factors below 10^17, so a(17) = 1.
CROSSREFS
For k-prime Carmichael numbers up to 10^n for k = 3,4,...,11, see A132195, A174612, A174613, A174614, A174615, A174616, A174617, A299710, A299711.
Cf. A002997, A006931, A055553.
Sequence in context: A110203 A263704 A166832 * A175775 A215117 A350982
Adjacent sequences: A299708 A299709 A299710 * A299712 A299713 A299714
KEYWORD
nonn,more,hard
AUTHOR
Tim Johannes Ohrtmann, Feb 17 2018
EXTENSIONS
a(22) from Claude Goutier added by Amiram Eldar, Apr 19 2024
a(23)-a(24) from Shallue and Webster (2025-2026) added by Amiram Eldar, Jan 24 2026
STATUS
approved

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Last modified May 21 18:11 EDT 2026. Contains 395802 sequences.
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