A010472 Decimal expansion of square root of 15.

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

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• cons

Comments

Continued fraction expansion is 3 followed by {1, 6} repeated. - Harry J. Smith, Jun 03 2009

Examples

			3.87298334620741688517926539978239961083292170529159082658757376611348309193...
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..20000
• Index entries for algebraic numbers, degree 2

Crossrefs

Cf. A040011 (continued fraction).

Programs

Maple

evalf[120](sqrt(15)); # Muniru A Asiru, Feb 12 2019

Mathematica

RealDigits[N[Sqrt[15],200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Feb 20 2011 *)

PARI

default(realprecision, 20080); x=sqrt(15); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010472.txt", n, " ", d));  \\ Harry J. Smith, Jun 03 2009

Formula

Equals 3 + Sum_{k>=0} (-1)^k * binomial(2*k,k)/((k+1) * 6^k). - Amiram Eldar, May 06 2022