A236290 Decimal expansion of (sqrt(33) - 1) / 2.

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

Offset

1,1

Comments

Decimal expansion of sqrt(8 - sqrt(8 - sqrt(8 - sqrt(8 - ... )))).

The sequence with a(1) = 3 is decimal expansion of sqrt(8 + sqrt(8 + sqrt(8 + sqrt(8 + ... )))).

A quadratic integer with minimal polynomial x^2 + x - 8. - Charles R Greathouse IV, Apr 21 2016

Triangular root of 4. - Stefano Spezia, Sep 05 2025

Links

Kelvin Voskuijl, Table of n, a(n) for n = 1..20000

Colin Foster, Triangular roots, Applied Probability Trust, pp. 8-9, 2012.

Index entries for algebraic numbers, degree 2.

Formula

Equals A235162 - 1.

Example

2.37228132326901432992530573410946465911013222899139618384993873528...

Maple

evalf((sqrt(33)-1)/2, 140);  # Alois P. Heinz, Sep 05 2025

Mathematica

RealDigits[(Sqrt[33] - 1)/2, 10, 130]

Prog

(PARI) (sqrt(33)-1)/2 \\ Charles R Greathouse IV, Apr 21 2016

Crossrefs

Cf. A010488, A235162.

Sequence in context: A358969 A205129 A396268 * A105273 A174925 A204986

Adjacent sequences: A236287 A236288 A236289 * A236291 A236292 A236293

Keyword

nonn,cons,easy

Author

Jaroslav Krizek, Feb 07 2014

Status

approved