A341764 The number of edges on a 2 by 1 ellipse formed by the straight line segments mutually connecting all points formed by dividing the ellipse into 2n equal angle sectors from its origin.

1, 8, 42, 148, 426, 984, 2022, 3604, 6138, 9492, 14642, 21108, 29902, 40728, 54786, 71604, 92722, 117384, 147578, 181810, 223782, 270808, 326262, 388308, 460446, 540424, 632322, 733364, 848318, 973732, 1115422, 1269108, 1441122, 1626888, 1833406, 2055444, 2300822, 2563544, 2852358, 3160050, 3497562

Offset

1,2

Comments

The terms are from numeric computation - no formula for a(n) is currently known.

See A341688 for a description of the ellipse and images of the regions, and A341762 for images of the vertices.

Links

Table of n, a(n) for n=1..41.

Wikipedia, Ellipse.

Formula

a(n) = A341688(n) + A341762(n) - 1.

Crossrefs

Cf. A341688 (regions), A341762 (vertices), A341800 (n-gons), A007678, A092867, A255011, A331929, A331931, A333075.

Sequence in context: A027903 A231069 A319235 * A256861 A287221 A119965

Adjacent sequences: A341761 A341762 A341763 * A341765 A341766 A341767

Keyword

nonn

Author

Scott R. Shannon and N. J. A. Sloane, Feb 19 2021

Status

approved