A207335 Number of minimal polynomials of 2*cos(Pi/N) with allowed degree given by A207333.

3, 3, 2, 4, 1, 4, 5, 2, 3, 1, 7, 1, 1, 6, 5, 6, 2, 2, 1, 9, 1, 1, 2, 1, 5, 7, 1, 1, 11, 1, 8, 1, 4, 4, 2, 13, 2, 1, 2, 1, 5, 1, 4, 2, 11, 1, 8, 1, 4, 1, 1, 2, 16, 1, 1, 4, 10

Offset: 1

Author

Wolfdieter Lang, Feb 19 2012

Keywords

• nonn
• easy

Comments

For the minimal polynomials C(N,x) of 2*cos(Pi/N) with degree delta(N) see A207333.

Examples

			a(8)=2 because there are exactly 2 values of N, namely 19 and 27 (see row no. 7 of the array A207334), for which the minimal polynomial C(N,x) has degree delta(N) = A207333(8) = 9.
		

Crossrefs

Cf. A207333, A143422.

Formula

a(n) is the number of different indices N of minimal polynomials C(N,x) of 2*cos(Pi/N) with allowed degree delta(N)=A207333(n), n>=1.