A064888 Numerators of partial sums of 1/A051451.

1, 2, 3, 23, 323, 647, 971, 7121, 6943, 185147, 363173, 179407463, 412637165, 20631858251, 140035237, 3716297449, 27822060851939, 2853544702763, 58823785801243, 568431869527163, 279209361758899949, 4944838261875010691

Offset

1,2

Comments

A051451 unlike A003418 contains distinct values of lcm(1..m).

Links

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

Formula

a(n) = Sum_{k=1..n} 1/A051451(k), where A051451 is the lcm(1...m), m is a prime or true power of prime. The sequence is convergent.

Example

n=6, s(n) = 1/2 + 1/6 + 1/12 + 1/60 + 1/420 + 1/840 = 646/840 = 323/420, the numerator is a(6)=323.

Mathematica

s=Select[Range[a, b], Equal[Length[FactorInteger[ # ]], 1]&] a(m) = Apply[LCM, Table[Part[s, w], {w, 1, m}]]

Crossrefs

Cf. A003418, A051451, A064857-A064859.

Sequence in context: A099656 A157733 A235934 * A104458 A191859 A289550

Adjacent sequences: A064885 A064886 A064887 * A064889 A064890 A064891

Keyword

frac,nonn

Author

Labos Elemer, Oct 10 2001

Status

approved