A298749 Decimal expansion of (1/2)(1 + sqrt(1 + 4*sqrt(5))).

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

Offset

1,1

Links

Clark Kimberling, Table of n, a(n) for n = 1..10000

Index entries for algebraic numbers, degree 4.

Formula

Minimal polynomial x^4-2*x^2+x^2-5. - R. J. Mathar, Jun 03 2026

Example

constant = 2.0767269825495438944... = positive zero of x^2 - x - sqrt(5).

Mathematica

r = (1/2)*(1 + Sqrt[1 + 4 Sqrt[5]])
RealDigits[N[r, 100], 10][[1]];  (* A298749 *)

Prog

(PARI) 1/2*(1+sqrt(1+4*sqrt(5))) \\ Charles R Greathouse IV, May 18 2026

Crossrefs

Cf. A275828, A298750, A298751, A298752.

Sequence in context: A178818 A354615 A113319 * A021832 A380794 A352615

Adjacent sequences: A298746 A298747 A298748 * A298750 A298751 A298752

Keyword

nonn,easy,cons,changed

Author

Clark Kimberling, Feb 13 2018

Status

approved