A242435 Number of terms of A182116 between 2^n and 2^(n+1).

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 2, 6, 2, 7, 8, 6, 12, 11, 21, 24, 27, 35, 45, 68, 86, 117, 176, 206, 260, 370, 457, 565, 750, 967, 1321, 1531, 1978, 2842, 3723, 4587, 5677, 8354, 10761, 13435, 17259, 23040, 31811, 40146, 48596, 66728, 92193, 112771, 149002, 209890, 270520, 341889, 438713, 634913

Offset

1,25

Comments

This was done with data on Carmichael numbers below 10^21 provided by R. G. E. Pinch, and special computational assistance from William Stein.

There are 16396564 Carmichael numbers below 2^69 but only 849752 have the property of A182116. It looks as though the ratio of Carmichael numbers of this type to normal Carmichael numbers converges to a value around 0.051.

Links

Table of n, a(n) for n=1..72.

Richard Pinch, Carmichael numbers up to 10^21.

Crossrefs

Cf. A002997, A182116, A182108, A182490.

Sequence in context: A062321 A229479 A086356 * A086359 A091944 A069936

Adjacent sequences: A242432 A242433 A242434 * A242436 A242437 A242438

Keyword

nonn

Author

Brad Clardy, May 14 2014

Extensions

a(57) and a(61) corrected and a(69)-a(72) added by Amiram Eldar, Feb 07 2026

Status

approved