A392444 Number of edges in a complete bipartite graph where the vertices in the two parts are placed on opposite sides of a parabola at integer y coordinates y = 1, 2, ...n.

1, 6, 27, 85, 222, 467, 912, 1594, 2609, 4054, 6075, 8686, 12167, 16540, 21993, 28678, 36903, 46622, 58323, 71949, 87894, 106379, 127720, 151877, 179415, 210620, 245697, 284923, 328884, 377417, 431478, 490875, 556316, 628129, 706614, 791838, 885223, 986460

Offset

1,2

Comments

See A392442 and A392443 for illustrations of the graphs.

Links

Table of n, a(n) for n=1..38.

Formula

a(n) = A392442(n) + A392443(n) - 1 by Euler's formula.

Crossrefs

Cf. A392442 (vertices), A392443 (regions), A392427 (integer x), A290132.

Sequence in context: A250283 A100188 A392427 * A131985 A125196 A377269

Adjacent sequences: A392441 A392442 A392443 * A392445 A392446 A392447

Keyword

nonn

Author

Scott R. Shannon, Jan 12 2026

Status

approved