

A324317


Number of primary Carmichael numbers (A324316) less than 10^n.


10



0, 0, 0, 2, 4, 9, 19, 51, 107, 219, 417, 757, 1470, 2666, 5040, 9280, 17210, 32039, 59762, 111811, 210627, 397968
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OFFSET

1,4


COMMENTS

The number of Carmichael numbers (A002997) less than 10^n is 0, 0, 1, 7, 16, 43, 105, 255, 646, 1547, 3605, 8241, 19279, 44706, 105212, 246683, 585355, 1401644, ... (see A055553).
The terms up to a(10) are given in Table 1 of Kellner and Sondow 2019. The terms up to a(18) and related results are given in Table 1.5 of Kellner 2019.
All computations depend on Pinch's database.


LINKS



EXAMPLE

There are two primary Carmichael numbers less than 10^4, namely, 1729 and 2821, so a(4) = 2.


CROSSREFS

Cf. A002997, A055553, A324315, A324316, A324318, A324319, A324320, A324369, A324370, A324371, A324404, A324405.


KEYWORD

nonn,base,more,hard


AUTHOR



EXTENSIONS



STATUS

approved



