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A174615
Number of seven-prime Carmichael numbers less than 10^n.
9
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 41, 262, 1340, 5359, 19210, 60150, 172234, 460553, 1159167, 2774702, 6363475, 14056367
OFFSET
0,11
LINKS
EXAMPLE
The smallest Carmichael number with 7 prime factors is 5394826801 = 7*13*17*23*31*67*73, and there is one other 10-digit example, so a(10)=2.
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.
Sequence in context: A212837 A063271 A142160 * A109125 A037061 A065587
KEYWORD
nonn,more
AUTHOR
Michel Lagneau, Mar 23 2010
EXTENSIONS
a(22) from Claude Goutier added by Amiram Eldar, Apr 19 2024
STATUS
approved