A328937 The number of imprimitive 3-Carmichael numbers (A087788 and A328935) below 10^n.

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

Table of n, a(n) for n=6..24.

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

Cf. A002997, A087788, A132195, A328935.

Sequence in context: A156127 A178742 A202088 * A328936 A266816 A289082

Adjacent sequences: A328934 A328935 A328936 * A328938 A328939 A328940

Keyword

nonn,more

Author

Amiram Eldar, Oct 31 2019

Status

approved