Polygamma Functions with Arbitrary Precision (Algorithm 349 [S14]) CACM April, 1969 Schwachheim, G. polygamma function, psi function, digamma function, trigamma function, tetragamma function, pentagamma function, special functions 5.12 CA690404 JB February 17, 1978 4:36 PM 1913 5 1913 1913 5 1913 1913 5 1913