A015620 Number of triples of different integers from [ 2,n ] with no common factors between pairs.

0, 0, 0, 2, 2, 8, 11, 18, 20, 42, 45, 79, 88, 102, 119, 183, 193, 277, 297, 335, 363, 491, 512, 619, 664, 756, 802, 1016, 1037, 1285, 1376, 1494, 1579, 1739, 1790, 2150, 2261, 2431, 2518, 2968, 3022, 3522, 3668, 3848, 4016, 4620, 4721, 5231, 5382

Offset

2,4

Links

Table of n, a(n) for n=2..50.

Crossrefs

Sequence in context: A202736 A179989 A046982 * A288053 A288506 A046690

Adjacent sequences: A015617 A015618 A015619 * A015621 A015622 A015623

Keyword

nonn

Author

Olivier Gérard

Status

approved