A360043 Number of edges in a Farey fan of order n.

4, 9, 18, 30, 52, 74, 112, 154, 210, 268, 352, 436, 552, 668, 802, 948, 1134, 1316, 1546, 1778, 2038, 2306, 2630, 2952, 3326, 3704, 4124, 4556, 5060, 5552, 6126, 6710, 7338, 7978, 8674, 9376, 10174, 10972, 11824, 12692, 13664, 14620, 15690, 16768, 17898, 19048, 20314, 21574, 22944, 24312

Offset: 1

Author

Scott R. Shannon, N. J. A. Sloane and M. Douglas McIlroy, Jan 23 2023

Keywords

• nonn

Comments

See the reference for the definition of a 'Farey fan'. See A360042 and A360044 for further details and images of the graph.

References

• McIlroy, M. D. "A Note on Discrete Representation of Lines". AT&T Technical Journal, 64 (1985), 481-490.

Crossrefs

Cf. A005598 (regions), A360042 (vertices), A360044 (k-gons), A005728, A174030, A359976, A359970, A359693.