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A328937
The number of imprimitive 3-Carmichael numbers (A087788 and A328935) below 10^n.
0
4, 11, 25, 59, 127, 252, 471, 928, 1734, 3462, 6615, 12725, 24396, 46877, 89854, 173331, 334737, 647265, 1253176
OFFSET
6,1
COMMENTS
Granville and Pomerance conjectured that most Carmichael numbers are imprimitive, i.e. lim_{n->oo} a(n)/A132195(n) = 1.
LINKS
J. M. Chick, Carmichael number variable relations: three-prime Carmichael numbers up to 10^24, arXiv preprint arXiv:0711.2915 [math.NT] (2007).
Andrew Granville and Carl Pomerance, Two contradictory conjectures concerning Carmichael numbers, Mathematics of Computation, Vol. 71, No. 238 (2002), pp. 883-908.
EXAMPLE
a(6) = 4 since there are 4 imprimitive 3-Carmichael numbers below 10^6: 294409, 399001, 488881, 512461.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Oct 31 2019
STATUS
approved