A369291 - OEIS

A369291

Array read by antidiagonals: T(n,k) = phi(k^n-1)/n, where phi is Euler's totient function (A000010), n >= 1, k >= 2.

1, 1, 1, 2, 2, 2, 2, 4, 4, 2, 4, 4, 12, 8, 6, 2, 12, 20, 32, 22, 6, 6, 8, 56, 48, 120, 48, 18, 4, 18, 36, 216, 280, 288, 156, 16, 6, 16, 144, 160, 1240, 720, 1512, 320, 48, 4, 30, 96, 432, 1120, 5040, 5580, 4096, 1008, 60, 10, 16, 216, 640, 5400, 6048, 31992, 14976, 15552, 2640, 176

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,4

COMMENTS

For k a prime power, T(n,k) is the number of primitive polynomials of degree n over GF(k). See A011260, A027385 for additional information.

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1275 (first 50 antidiagonals)

Eric Weisstein's World of Mathematics, Totient Function.

Wikipedia, Euler's totient function.

EXAMPLE

Array begins:

n\k| 2 3 4 5 6 7 8 9 ...