OFFSET

1,1

COMMENTS

a(30) > 8040423200947.

LINKS

Lucas A. Brown, semiprimemods.py.

EXAMPLE

The 1st semiprime is 4, which is congruent to 7 (mod 1), so 4 is in the sequence.

The 2nd semiprime is 6, which is not congruent to 7 (mod 2), so 6 is not in the sequence.

The 3rd semiprime is 9, which is not congruent to 7 (mod 3), so 9 is not in the sequence.

The 7th semiprime is 21, which is congruent to 7 (mod 7), so 21 is in the sequence.

CROSSREFS

KEYWORD

nonn,hard

AUTHOR

Lucas A. Brown, Oct 15 2022

STATUS

approved