A064890 Decimal expansion of the sum of reciprocals of A051451, which includes 1 and values of lcm(1,...,x), where x is a prime power (A000961).

1, 7, 7, 0, 6, 7, 5, 2, 4, 4, 3, 2, 5, 5, 8, 0, 2, 2, 7, 9, 1, 9, 7, 9, 6, 0, 0, 7, 6, 4, 2, 6, 6, 0, 8, 0, 2, 2, 3, 3, 1, 8, 3, 7, 6, 7, 2, 7, 2, 8, 3, 3, 5, 2, 0, 5, 2, 2, 4, 5, 8, 9, 6, 4, 4, 1, 2, 2, 2, 0, 3, 3, 8, 1, 0, 2, 2, 9, 6, 1, 1, 0, 5, 6, 5, 0, 7, 0, 5, 7, 7, 5, 7, 0, 8, 0, 9, 3, 4, 0, 3, 3, 3, 0, 2

Offset

1,2

Links

Table of n, a(n) for n=1..105.

Example

c = 1.7706752443255802279197960076426608022331837672728335205224589644122203381...
c = 1 + (1/2) + (1/6) + (1/12) + (1/60) + (1/420) + ... = 743/420 + ... = 1.7690 + ... = 1.7706752... Compare with A064859, an analogous constant obtained from A003418, where the constant is larger than c: 1.7877805 > 1.7706752. Repeated occurrences of LCM values in A003418 is responsible for the 1.78778... - 1.77067... = 0.0171... excess.

Mathematica

f[n_] := LCM @@ Range@ n; RealDigits[ Plus @@ (1/Union@ Array[f, 251]), 10, 111][[1]] (* Robert G. Wilson v, Jul 11 2011 *)

Crossrefs

Cf. A051451, A003418, A064859, A000961.

Sequence in context: A215735 A344382 A019725 * A196602 A200622 A357102

Adjacent sequences: A064887 A064888 A064889 * A064891 A064892 A064893

Keyword

cons,nonn

Author

Labos Elemer, Oct 11 2001

Status

approved