A144971 Integers of the form sum_{i=2521..j} i/(i-2520) for any upper limit j.

2521, 3782, 4623, 5254, 5759, 6180, 6541, 6857, 7138, 7391

Offset

1,1

Links

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

Example

The sum of the fractions i/(i-2520) over 2521<=i<=j is integer for upper limits j=2521 up to j=2530, which define the first 10 values of the sequence, for example a(3) = 2521/(2521-2520) +2522/(2522-2520) +2523/(2523-2520) = 4623.

Mathematica

lst={}; q=2520; s=0; Do[s+=n/(n-q); If[s==IntegerPart[s], AppendTo[lst, s]], {n, q+1, q+4!}]; lst

Crossrefs

Sequence in context: A172684 A172652 A217862 * A217588 A264339 A045942

Adjacent sequences: A144968 A144969 A144970 * A144972 A144973 A144974

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Sep 27 2008

Extensions

Rephrased definition. Changed offset to 1. Added example. - R. J. Mathar, Oct 01 2008

Status

approved