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A059246 Numerator of Sum_{j=1..n} d(j)/n, where d = number of divisors function (A000005). 3
1, 3, 5, 2, 2, 7, 16, 5, 23, 27, 29, 35, 37, 41, 3, 25, 52, 29, 60, 33, 10, 37, 76, 7, 87, 7, 95, 101, 103, 37, 113, 119, 41, 127, 131, 35, 142, 73, 50, 79, 160, 4, 170, 4, 182, 93, 4, 33, 201, 207, 211, 217, 219, 227, 21, 239, 81, 247, 249, 87, 263 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

M. Aigner and G. M. Ziegler, Proofs from The Book, Springer-Verlag, Berlin, 1999; see p. 135.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = numerator(A006218(n)/n). - Michel Marcus, Jan 03 2017

EXAMPLE

1, 3/2, 5/3, 2, 2, 7/3, 16/7, 5/2, 23/9, 27/10, ...

MATHEMATICA

Numerator[Table[Sum[DivisorSigma[0, j]/n, {j, 1, n}], {n, 1, 100}]] (* G. C. Greubel, Jan 02 2017 *)

PROG

(PARI) a(n) = numerator(sum(j=1, n, numdiv(j))/n); \\ Michel Marcus, Jan 03 2017

CROSSREFS

Cf. A006218, A059247.

Sequence in context: A243524 A272300 A115406 * A091276 A282574 A076562

Adjacent sequences:  A059243 A059244 A059245 * A059247 A059248 A059249

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Jan 21 2001

STATUS

approved

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Last modified August 23 13:45 EDT 2019. Contains 326227 sequences. (Running on oeis4.)