A106132 Numbers k such that the k-th semiprime == 7 (mod k).

1, 7, 9, 66, 6675, 6918, 613374, 613412, 613418, 613422, 613428, 613434, 613510, 613512, 613514, 613520, 613542, 58155531, 58155569, 58155572, 6384425518, 6384425556, 819217006165, 819217006175, 819217006199, 819217006203, 819217006227, 819217006665, 819217006869

Offset: 1

Author

Shyam Sunder Gupta, May 07 2005

Keywords

• hard
• nonn

Comments

a(30) > 10^12. - Lucas A. Brown, Oct 18 2020

Examples

			a(3)=9 is a term because the 9th semiprime (i.e., 25) == 7 (mod 9).
		

Links

• Lucas A. Brown, semiprimemods.py

Crossrefs

Cf. A001358, A356357.

Extensions

a(18)-a(20) from Donovan Johnson, Oct 29 2008

a(21)-a(29) by Lucas A. Brown, Oct 18 2020

a(1), a(2) by Lucas A. Brown, Nov 22 2020