A119756 Numerator of n/1^n + (n-1)/2^n + (n-2)/3^n + ... + 2/(n-1)^n + 1/n^n.

1, 9, 355, 87425, 666094597, 283878143843, 1354313329376085811, 24568316785788956621809, 3695039511560825652073500196447, 20673934657221575836904008710237871

Offset

1,2

Comments

a(p-1) is divisible by p^2 for prime p>2. a(p-2) is divisible by p for prime p>3. a(n) = (n+1)*(Zeta[n] - Zeta[n,n+1]) - Zeta[n-1] + Zeta[n-1,n+1].

Links

Table of n, a(n) for n=1..10.

Formula

a(n) = numerator[ Sum[ (n+1-i)/i^n, {i,1,n} ]].

Mathematica

Table[Numerator[Sum[(n+1-i)/i^n, {i, 1, n}]], {n, 1, 13}]

Crossrefs

Sequence in context: A203745 A012812 A266881 * A222697 A063068 A130558

Adjacent sequences: A119753 A119754 A119755 * A119757 A119758 A119759

Keyword

frac,nonn

Author

Alexander Adamchuk, Jun 17 2006

Status

approved