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

1,2

Comments

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

Links

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

Lucas A. Brown, semiprimemods.py

Example

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

Crossrefs

Cf. A001358, A357807.

Sequence in context: A358669 A130317 A019467 * A119186 A119115 A079653

Adjacent sequences: A106125 A106126 A106127 * A106129 A106130 A106131

Keyword

hard,nonn

Author

Shyam Sunder Gupta, May 07 2005

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

Status

approved