A200064 Decimal expansion of the negated value of the digamma function at 2/3.

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

Offset: 1

Author

R. J. Mathar, Nov 13 2011

Keywords

• cons
• nonn

Examples

			psi(2/3) = -1.3182344157865884724023408166...
		

Links

• Wikipedia, Digamma function
• Index entries for sequences related to the digamma function

Crossrefs

Cf. A020759, A047787, A020777

Programs

Mathematica

RealDigits[ -PolyGamma[2/3], 10, 98] // First (* Jean-François Alcover, Feb 20 2013 *)

PARI

-psi(2/3) \\ Charles R Greathouse IV, Nov 22 2011

Formula

psi(2/3) = -gamma+Pi*sqrt(3)/6-3*log(3)/2 = A093602 - A047787 = 1.813799 -3.132033...