A237873 Denominator of Sum_{i=1..n} n^i/i.

1, 1, 2, 3, 12, 5, 20, 105, 280, 63, 2520, 385, 5544, 6435, 8008, 45045, 144144, 85085, 116688, 2909907, 739024, 146965, 232792560, 37182145, 356948592, 128707425, 2974571600, 717084225, 80313433200, 215656441, 30247916400, 4512611027925, 486207248800

Offset

1,3

Comments

The sequence gives the denominators of -n^(n+1)*Phi(n,1,n+1)-log(-n+1) for n>1, where Phi is the Lerch transcendent.

Links

Bruno Berselli, Table of n, a(n) for n = 1..200

Mathematica

f[n_] := Sum[n^i/i, {i, 1, n}]; Table[Denominator[f[n]], {n, 1, 40}]

Prog

(Magma) terms:=40; s:=[&+[n^i/i: i in [1..n]]: n in [1..terms]]; [Denominator(s[n]): n in [1..terms]];

Crossrefs

Cf. A236772, A237872 (numerators)

Sequence in context: A081369 A147967 A120487 * A069220 A301276 A062957

Adjacent sequences: A237870 A237871 A237872 * A237874 A237875 A237876

Keyword

nonn,frac

Author

Bruno Berselli, Feb 14 2014

Status

approved