A118975 Triangular array: row n consists of M times n-th-order Farey fractions, where M is the LCM of their denominators.

1, 1, 2, 2, 3, 4, 6, 3, 4, 6, 8, 9, 12, 12, 15, 20, 24, 30, 36, 40, 45, 48, 60, 10, 12, 15, 20, 24, 30, 36, 40, 45, 48, 50, 60, 60, 70, 84, 105, 120, 140, 168, 180, 210, 240, 252, 280, 300, 315, 336, 350, 360, 420, 105, 120, 140, 168, 210, 240

Offset

1,3

Comments

The multiplier M(n) = A003418(n). Column 1 is A002944(n) = (1/n)*lcm(1,2,...,n). The numbers in row n are relatively prime (unlike the related array A093594).

Links

Table of n, a(n) for n=1..59.

Example

Row 4 is 12*(1/4, 1/3, 1/2, 2/3, 3/4, 1).
First 5 rows:
   1
   1  2
   2  3  4  6
   3  4  6  8  9 12
  12 15 20 24 30 36 40 45 48 60.

Crossrefs

Cf. A003418.

Sequence in context: A083702 A074077 A078381 * A215644 A288777 A343503

Adjacent sequences: A118972 A118973 A118974 * A118976 A118977 A118978

Keyword

nonn,tabf

Author

Clark Kimberling, May 07 2006

Status

approved