This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A219277 #11 Jul 23 2025 14:25:30
%S A219277 3,4,7,15,18,19,37,43,46,47,62,74,75,84,89,90,92,96,105,112,130,139,
%T A219277 158,163,182,189,190,202,213,217,218,225,233,255,256,271,280,288,293,
%U A219277 301,314,317,329,335,337,349,350,354,360,364,365,368,376,396,416,422
%N A219277 Numbers n such that ChebyshevT[8,n] is prime.
%C A219277 ChebyshevT[8,x] is the 8th Chebyshev polynomial of the first kind evaluated at x.
%C A219277 The corresponding primes are in A144132.
%H A219277 Harvey P. Dale, <a href="/A219277/b219277.txt">Table of n, a(n) for n = 1..1000</a>
%t A219277 lst={}; Do[If[PrimeQ[ChebyshevT [8, n]], AppendTo[lst, n]], {n, 10^3}]; lst
%t A219277 Select[Range[500],PrimeQ[ChebyshevT[8,#]]&] (* _Harvey P. Dale_, Jul 23 2025 *)
%o A219277 (PARI) is(n)=ispseudoprime(polchebyshev(8,1,n)) \\ _Charles R Greathouse IV_, May 22 2017
%Y A219277 Cf. A144131, A144132.
%K A219277 nonn
%O A219277 1,1
%A A219277 _Michel Lagneau_, Nov 17 2012