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A175531
Carmichael numbers of order 2.
3
443372888629441, 39671149333495681, 842526563598720001, 2380296518909971201, 3188618003602886401, 4208895375600667752001
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OFFSET
1,1
COMMENTS
Odd composite integer k is in this sequence if k == 1 or p (mod p^2  1) for every prime pk.
LINKS
Table of n, a(n) for n=1..6.
Claude Goutier,
Compressed text file carm10e22.gz containing all the Carmichael numbers up to 10^22
.
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
EXTENSIONS
a(6) calculated using data from
Claude Goutier
and added by
Amiram Eldar
, Apr 20 2024
STATUS
approved
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Last modified June 18 14:16 EDT 2024. Contains 373481 sequences. (Running on oeis4.)