A106134 Numbers k such that the k-th semiprime == 9 (mod k).

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, Table of n, a(n) for n = 1..42

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

Adjacent sequences: A106131 A106132 A106133 * A106135 A106136 A106137

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