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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A383955 Decimal expansion of sqrt(5/3 - 2*sqrt(1/45)).

Original entry on oeis.org

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

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Author

Peter Kagey, Aug 19 2025

Keywords

Comments

Let v_10 be a degree-10 vertex and v_3 be a degree-3 vertex of a triakis icosahedron centered at the origin. Then this is the ratio of norm(v_10)/norm(v_3).
The minimal polynomial is 45*x^4 - 150*x^2 + 121.
One choice of coordinates for the triakis icosahedron describes a degree-10 vertex of the triakis icosahedron as (0,1,(1+sqrt(5)/2)) and a degree-3 vertex as (5+7*sqrt(5)/22*(1, 1, 1).

Examples

			1.169839420461925922675809622142811611361278...

Links

Crossrefs

Cf. A378973, A378974, A378975, A378976, A378977, A380793, A380794, A382009.

Programs

  • Mathematica
    RealDigits[Sqrt[(25 - 2*Sqrt[5])/15], 10, 100][[1]]
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