A091899 Decimal expansion of (1+sqrt(5)+sqrt(2*(5+sqrt(5))))/(2*e^((2*Pi)/5)).

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

Offset: 1

Author

Eric W. Weisstein, Feb 09 2004

Keywords

• nonn
• cons

Comments

Has a nice (non-simple) continued fraction due to Ramanujan.

Examples

			1.00186743...
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Ramanujan Continued Fractions

Crossrefs

Cf. A091667.

Programs

Magma

SetDefaultRealField(RealField(100)); R:= RealField(); (1 +Sqrt(5) +Sqrt(2*(5 +Sqrt(5))))/(2*Exp((2*Pi(R))/5)); // G. C. Greubel, Sep 27 2018

Mathematica

RealDigits[(1 +Sqrt[5] +Sqrt[2*(5 +Sqrt[5])])/(2*Exp[(2*Pi)/5]), 10, 100][[1]] (* G. C. Greubel, Sep 27 2018 *)

PARI

default(realprecision, 100); (1 +sqrt(5) +sqrt(2*(5 +sqrt(5))))/( 2*exp((2*Pi)/5)) \\ G. C. Greubel, Sep 27 2018

Formula

Equals 1/A091667.

Extensions

Offset corrected by R. J. Mathar, Feb 05 2009