References to A000252

Number of invertible 2 X 2 matrices mod n.
1, 6, 48, 96, 480, 288, 2016, 1536, 3888, 2880, 13200, 4608, 26208, 12096, 23040

1 seqfan posts

Fri Oct 29 05:35:16 CEST 2010    [seqfan] Implementing first 500 sequences in Java
Index of A-numbers in seqfan: by ascending order    by month    by frequency    by keyword
Links to OEIS content are included according to The OEIS End-User License Agreement .