A010782 Decimal expansion of 20th root of 2.

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

Offset

1,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Index entries for algebraic numbers, degree 20.

Formula

Equals Product_{k>=0} (1 + (-1)^k/(20*k + 19)). - Amiram Eldar, Aug 01 2020

Mathematica

RealDigits[N[2^(1/20), 100]][[1]] (* Vladimir Joseph Stephan Orlovsky, Jan 25 2012 *)
(* Alternative: *)
RealDigits[Surd[2, 20], 10, 120][[1]] (* Harvey P. Dale, Feb 06 2020 *)

Prog

(PARI) sqrtn(2, 20) \\ Charles R Greathouse IV, Apr 15 2014

Crossrefs

Cf. k-th root of 2: A002193 (k=2), A002580 (k=3), A010767 (k=4), A005531 (k=5), A010768-A010782 (k=6-20).

Sequence in context: A016657 A372143 A302793 * A333111 A139584 A064790

Adjacent sequences: A010779 A010780 A010781 * A010783 A010784 A010785

Keyword

nonn,cons,changed

Author

N. J. A. Sloane

Status

approved