A384156 Number of group Schur rings of the cyclic group Z_n.

1, 1, 2, 3, 3, 7, 4, 10, 7, 10, 4, 32, 6, 13, 21, 37, 5, 42, 6, 47, 27, 13, 4, 172, 13, 19, 25, 61, 6, 147, 8, 151, 27, 16, 41, 284, 9, 19, 41, 262, 8, 188, 8, 61, 140, 13, 4, 1033, 21, 79, 35, 91, 6, 232, 41, 334, 40, 19, 4, 1103, 12, 25, 187, 657, 67, 147, 8, 77, 27, 281, 8, 2311

Offset

1,3

Links

Table of n, a(n) for n=1..72.

Andrew Misseldine, Counting Schur Rings over Cyclic Groups, arXiv preprint arXiv:1508.03757 [math.RA], 2015.

Andrew Misseldine, Enumeration Techniques on Cyclic Schur Rings, arXiv preprint arXiv:2112.03422 [math.GR], 2021.

Matan Ziv-Av, Enumeration of Schur Rings Over Small Groups, Lecture Notes in Computer Science, International Workshop on Computer Algebra in Scientific Computing, Sept 2014. DOI:10.1007/978-3-319-10515-4_35

Crossrefs

Cf. A270785, A270786, A270787, A270789, A112951.

Sequence in context: A168140 A333699 A088100 * A097359 A358182 A393963

Adjacent sequences: A384153 A384154 A384155 * A384157 A384158 A384159

Keyword

nonn

Author

Joseph E. Marrow, May 20 2025

Extensions

Corrected and extended by Joseph E. Marrow, Mar 25 2026

Status

approved