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A142862
Semiprimes n (A001358) for which A000001(n) is 1.
1
15, 33, 35, 51, 65, 69, 77, 85, 87, 91, 95, 115, 119, 123, 133, 141, 143, 145, 159, 161, 177, 185, 187, 209, 213, 215, 217, 221, 235, 247, 249, 259, 265, 267, 287, 295, 299, 303, 319, 321, 323, 329, 335, 339, 341, 365, 371, 377, 391, 393, 395, 403, 407, 411
OFFSET
1,1
COMMENTS
Semiprimes pq with p<q and gcd(p,q-1)=1. - T. D. Noe, Oct 08 2008
REFERENCES
D. S. Dummit and R. M. Foote, Abstract Algebra, Wiley, 3rd Edition, 2003, page 135.
LINKS
John H. Conway, Heiko Dietrich and E. A. O'Brien, Counting groups: gnus, moas and other exotica.
MATHEMATICA
Select[Select[Range[1000], FactorInteger[#][[All, 2]] == {1, 1} &], !
Divisible[FactorInteger[#][[2, 1]] - 1, FactorInteger[#][[1, 1]]] &] (* Geoffrey Critzer, Nov 07 2015 *)
CROSSREFS
Sequence in context: A338468 A337984 A050384 * A053343 A068081 A089967
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 03 2008
EXTENSIONS
More terms from R. J. Mathar, Oct 04 2008
STATUS
approved