A280338 Number of sizes of remainder sets for n, for any natural number c, given natural number b in (b^c) mod n.

1, 1, 2, 2, 3, 2, 4, 3, 4, 3, 4, 3, 6, 4, 3, 3, 5, 4, 6, 5, 4, 4, 4, 4, 6, 6, 6, 6, 6, 3, 8, 6, 4, 5, 6, 6, 9, 6, 6, 6, 8, 4, 8, 7, 7, 4, 4, 5, 8, 6, 5, 9, 6, 6, 6, 8, 6, 6, 4, 5, 12, 8, 6, 7, 6, 4, 8, 9, 4, 6, 8, 8, 12, 9, 7, 10, 8, 6, 8, 6, 9, 8, 4, 6, 5, 8

Offset

1,3

Links

Jeptha Davenport, Table of n, a(n) for n = 1..500

Example

For a(1): b^c mod 1 = 0, so only 1 remainder set (0) is possible, and its size is 1.
For a(2): for any b, b^c will be even if b is even, or odd if b is odd, so b^c mod 2 has only 1 remainder for a given b (either (0), size 1, or (1), also size 1).
For a(5): choosing c for an arbitrary b, for b = 2, 2^2 mod 5 = 4, 2^3 mod 5 = 3, 2^4 mod 5 = 1, 2^5 mod 5 = 2, 2^6 mod 5 = 4, etc. (4 remainders); for base 4, 4^1 mod 5 = 4, 4^2 mod 5 = 1, 4^3 mod 5 = 4, etc. (2 remainders); for base 21, 21^1 mod 5 = 1, 21^819 mod 5 = 1, etc. (1 remainder); these are the only numbers of remainders which occur for any c given b for b^c modulo 5, so the number of remainder set sizes for n = 5 is 3 (4, 2, or 1-size remainder sets).
For a(100): number of remainder set sizes possible for any c given b is 10 (1, 2, 3, 4, 5, 6, 10, 11, 20, or 21-size remainder sets).

Crossrefs

First differs from A062821 at index n=15.

Sequence in context: A363685 A339666 A318881 * A339147 A062821 A353862

Adjacent sequences: A280335 A280336 A280337 * A280339 A280340 A280341

Keyword

nonn

Author

Jeptha Davenport, Dec 31 2016

Status

approved