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A106134
Numbers k such that the k-th semiprime == 9 (mod k).
1
1, 3, 5, 6, 13, 15, 80, 86, 6905, 6907, 6908, 6913, 6917, 613373, 613409, 613420, 613421, 613430, 613506, 613534, 613573, 613578, 613600, 58155529, 58155553, 6384425450, 6384425452, 6384425462, 6384425495, 6384425507, 6384425515, 6384425554, 6384425578, 6384425648
OFFSET
1,2
COMMENTS
a(43) > 10^12. - Lucas A. Brown, Nov 22 2020
LINKS
Lucas A. Brown, semiprimemods.py
EXAMPLE
a(5)=13 is a term because the 13th semiprime (i.e., 35) == 9 (mod 13).
CROSSREFS
Cf. A001358.
Sequence in context: A139013 A108337 A285534 * A064519 A331398 A048968
KEYWORD
nonn,hard
AUTHOR
Shyam Sunder Gupta, May 07 2005
EXTENSIONS
a(24)-a(25) from Donovan Johnson, Oct 29 2008
a(1)-a(4), a(26)-a(42) by Lucas A. Brown, Nov 22 2020
STATUS
approved