A091682 Decimal expansion of 2*(18 + sqrt(3)*Pi)/27.

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

Offset: 1

Author

Eric W. Weisstein, Jan 28 2004

Keywords

• nonn
• cons

Comments

Also, decimal expansion of Sum_{h >= 0} 1/binomial(2*h,h). [From Renzo Sprugnoli]

Examples

			1.736399858718715077909795168364923496063125832909497905682196652308471818...
		

Links

• Michael Penn, So many factorials!!!, YouTube video, 2020.
• Renzo Sprugnoli, Sums of Reciprocals of the Central Binomial Coefficients, INTEGERS, 6 (2006), #A27, page 9.
• Eric Weisstein's World of Mathematics, Factorial Sums
• Index entries for transcendental numbers

Crossrefs

Cf. A248179: decimal expansion of Sum_{h >= 0} 1/binomial(2*h+1,h).

Programs

Mathematica

RealDigits[N[(2 (18 + Pi Sqrt@3))/27, 120]] // First (* Michael De Vlieger, Sep 11 2015 *)

PARI

default(realprecision,2000); 2*(18 + sqrt(3)*Pi)/27 \\ Anders Hellström, Sep 11 2015

Formula

Sum_{n>=0} (n!)^2/(2n)!.

Equals A073016 plus 1. - R. J. Mathar, Sep 08 2008