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 A219281 #8 Aug 13 2018 09:10:57
%S A219281 2,2,2,3,2,8,164,29,60,213,181,652
%N A219281 Smallest number k such that ChebyshevT[2^n, k] is prime.
%C A219281 ChebyshevT[2^n,x] is the 2^n th Chebyshev polynomial of the first kind evaluated at x.
%e A219281 T(1, x) = x => T(1,2) = 2 is prime => a(0) = 2;
%e A219281 T(2, x) = 2x^2 - 1 => T(2, 2) = 7 is prime => a(1) = 2;
%e A219281 T(4, x) = 8x^4 - 8x^2 + 1 => T(4,2) = 97 is prime => a(2) = 2.
%p A219281 for n from 0 to 11 do
%p A219281 P:= unapply(orthopoly[T](2^n,x),x):
%p A219281 for k from 1 do if isprime(P(k)) then A[n]:= k; break fi od
%p A219281 od:
%p A219281 seq(A[n],n=0..11); # _Robert Israel_, Aug 13 2018
%t A219281 Table[k = 0; While[!PrimeQ[ChebyshevT[2^n,k]], k++]; k, {n, 0, 7}]
%Y A219281 Cf. A066436, A144131, A144132, A219276, A219277, A219278, A219279, A219280.
%K A219281 nonn,hard,more
%O A219281 0,1
%A A219281 _Michel Lagneau_, Nov 17 2012
%E A219281 a(10) and a(11) from _Robert Israel_, Aug 13 2018