A299101 Indices of (probable) primes in A030221.

2, 3, 5, 6, 8, 9, 15, 18, 23, 53, 114, 194, 564, 575, 585, 2594, 3143, 4578, 4970, 9261, 11508, 13298, 30018, 54993, 198476

Offset: 1

Author

L. Edson Jeffery, Bob Selcoe and Andrew Hone, Feb 02 2018

Keywords

• nonn
• hard
• more

Comments

From a problem in A269254. For detailed theory, see [Hone].

a(25) > 2*10^5. - Robert Price, Jul 03 2020

Links

• Andrew N. W. Hone, et al., On a family of sequences related to Chebyshev polynomials, arXiv:1802.01793 [math.NT], 2018.

Crossrefs

Cf. A269254, A030221, A294099 (row 5).

Cf. A285992, A299107, A299109, A088165, A117522, A299100, A299101, A113501, A269253, A298675, A298677, A298878, A299045, A299071.

Programs

Mathematica

-1 + Position[Nest[Append[#, 5 #[[-1]] - #[[-2]] ] &, {1, 6}, 2600], ?PrimeQ][[All, 1]] (* _Michael De Vlieger, Jul 03 2020 *)

Formula

A299109(n) = A030221(a(n)). - R. J. Mathar, Jul 22 2022

Extensions

a(24) from Robert Price, Jul 03 2020