

A175531


Carmichael numbers of order 2.


3




OFFSET

1,1


COMMENTS

Odd composite integer n is in this sequence if n == 1 or p (mod p^2  1) for every prime pn.
No other terms below 10^21.


LINKS

Table of n, a(n) for n=1..5.
Everett W. Howe, Higherorder Carmichael numbers, Math. Comp. 69 (2000), 17111719. doi:10.1090/S0025571800012254


CROSSREFS

Subsequence of A002997, A175530, and A299799.
Sequence in context: A261150 A181392 A299799 * A186914 A172665 A172601
Adjacent sequences: A175528 A175529 A175530 * A175532 A175533 A175534


KEYWORD

nonn,hard,more


AUTHOR

Max Alekseyev, Jun 08 2010


STATUS

approved



