A374971 Decimal expansion of the apothem (inradius) of a regular heptagon with unit side length.

1, 0, 3, 8, 2, 6, 0, 6, 9, 8, 2, 8, 6, 1, 6, 8, 2, 8, 3, 5, 8, 1, 7, 6, 9, 4, 3, 0, 7, 4, 2, 9, 2, 0, 1, 6, 5, 3, 5, 2, 8, 6, 0, 1, 0, 3, 3, 1, 2, 9, 8, 4, 2, 6, 2, 0, 4, 1, 7, 0, 8, 6, 8, 8, 4, 3, 1, 5, 1, 4, 2, 4, 3, 5, 3, 2, 2, 9, 8, 8, 5, 8, 7, 3, 2, 2, 0, 8, 7, 7

Offset

1,3

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Regular Polygon.

Wikipedia, Apothem.

Formula

Equals cot(Pi/7)/2 = A178818/2.

Equals 1/(2*tan(Pi/7)) = 1/(2*A343058).

Equals A374957*cos(Pi/7) = A374957*A073052.

Equals A374957 - A374972.

Example

1.0382606982861682835817694307429201653528601033...

Mathematica

First[RealDigits[Cot[Pi/7]/2, 10, 100]]

Crossrefs

Cf. A374957 (circumradius), A374972 (sagitta), A178817 (area).

Cf. apothem of other polygons with unit side length: A020769 (triangle), A020761 (square), A375067 (pentagon), A010527 (hexagon), A174968 (octagon), A375152 (9-gon), A179452 (10-gon), A375191 (11-gon), A375193 (12-gon).

Cf. A178818, A073052, A343058.

Sequence in context: A220516 A010627 A103712 * A327951 A132019 A182168

Adjacent sequences: A374968 A374969 A374970 * A374972 A374973 A374974

Keyword

nonn,cons,easy

Author

Paolo Xausa, Jul 26 2024

Status

approved