A144167 a(n) = IntegerPart(PolyGamma(n,1)).

1, -2, 6, -24, 122, -726, 5060, -40400, 363240, -3630593, 39926622, -479060379, 6227402193, -87180957830, 1307694352218, -20922949679481, 355688785859223, -6402385922818921, 121645216453639396, -2432903168507861321, 51090954354370285677, -1124000861780891230602

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Formula

a(n) = (-1)^(n+1)*floor(n!*zeta(n+1)). - Jean-François Alcover, Feb 28 2013

Mathematica

lst={}; Do[AppendTo[lst, IntegerPart[PolyGamma[n, 1]]], {n, 4^3}]; lst

Crossrefs

Cf. A144168, A144169, A144170.

Sequence in context: A349089 A352429 A352437 * A104983 A375458 A144251

Adjacent sequences: A144164 A144165 A144166 * A144168 A144169 A144170

Keyword

sign

Author

Vladimir Joseph Stephan Orlovsky, Sep 12 2008

Extensions

a(21)-a(22) from Stefano Spezia, Dec 09 2025

Status

approved