A376931 Number of points out of n points placed on a circle that can never be reached when starting at one point and then moving clockwise in incrementally increasing steps (first 1, then 2, 3, 4, ...).

0, 0, 1, 0, 2, 2, 3, 0, 5, 4, 5, 4, 6, 6, 9, 0, 8, 10, 9, 8, 13, 10, 11, 8, 14, 12, 16, 12, 14, 18, 15, 0, 21, 16, 23, 20, 18, 18, 25, 16, 20, 26, 21, 20, 33, 22, 23, 16, 27, 28, 33, 24, 26, 32, 37, 24, 37, 28, 29, 36, 30, 30, 47, 0, 44, 42, 33, 32, 45, 46, 35

Offset

1,5

Comments

Put n distinct points on the edge of a circle. Connect the first to the point 1 step clockwise from it, then connect that one to the point 2 steps clockwise from that, continuing with 3 steps, 4 steps, etc. In the end, a(n) is the number of points never landed on.

Links

Table of n, a(n) for n=1..71.

Formula

a(n) = n - A117484(n).

Crossrefs

Cf. A117484.

Sequence in context: A330925 A191361 A199784 * A349384 A127466 A342314

Adjacent sequences: A376928 A376929 A376930 * A376932 A376933 A376934

Keyword

nonn

Author

Payton Richards, Oct 11 2024

Status

approved