A106128 Numbers k such that the k-th semiprime == 3 (mod k).

1, 3, 6, 36, 46, 78, 6915, 6916, 613375, 613378, 613404, 613406, 613414, 613438, 613448, 613454, 613456, 613508, 613519, 613522, 613532, 613559, 613568, 613570, 613582, 613586, 613598, 58155528, 58155536, 58155549, 6384425454, 6384425520, 6384425522, 6384425528, 6384425638

Offset: 1

Author

Shyam Sunder Gupta, May 07 2005

Keywords

• hard
• nonn

Comments

a(48) > 10^12. - Lucas A. Brown, Oct 13 2022

Examples

			a(3) = 6 is a term because the 6th semiprime is 15 and 15 == 3 (mod 6).
		

Links

• Lucas A. Brown, Table of n, a(n) for n = 1..47
• Lucas A. Brown, semiprimemods.py

Crossrefs

Cf. A001358, A357807.

Extensions

a(28)-a(30) from Donovan Johnson, Oct 29 2008

a(1), a(2), and a(31)-a(47) by Lucas A. Brown, Oct 19 2020