A344212 Decimal expansion of 1 + 1/sqrt(5).

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

Offset

1,2

Comments

Decimal expansion of the midradius of a rhombic triacontahedron with unit edge length.

Essentially the same sequence of digits as A176453, A134974, A020762 and A010476. - R. J. Mathar, May 16 2021

Links

Table of n, a(n) for n=1..93.

Wikipedia, Rhombic triacontahedron.

Formula

From Amiram Eldar, Nov 28 2024: (Start)

Equals 2*A242671 = 1/A187798.

Equals Product_{k>=0} (1 + 1/A081005(k)). (End)

Example

1.447213595499957939281834733746255247088123671922305...

Mathematica

RealDigits[1 + 1/Sqrt[5], 10, 100][[1]] // Flatten

Crossrefs

Cf. A019952 (rhombic triacontahedron inscribed sphere radius).

Cf. A344171 (rhombic triacontahedron surface area).

Cf. A344172 (rhombic triacontahedron volume).

Cf. A010476, A020762, A081005, A134974, A176453, A187798, A242671.

Sequence in context: A196463 A021695 A131844 * A010476 A020762 A204158

Adjacent sequences: A344209 A344210 A344211 * A344213 A344214 A344215

Keyword

nonn,cons

Author

Wesley Ivan Hurt, May 11 2021

Status

approved