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A219276
Numbers n such that T_4(n) is prime, where T_4(x) = 8x^4 - 8x^2 + 1 is the fourth Chebyshev polynomial (of the first kind).
4
2, 3, 5, 8, 10, 14, 17, 19, 31, 32, 34, 35, 39, 48, 50, 51, 53, 54, 59, 61, 73, 76, 78, 84, 88, 90, 97, 101, 102, 105, 107, 110, 121, 126, 128, 134, 135, 139, 143, 144, 146, 152, 153, 158, 167, 171, 172, 178, 180, 184, 186, 187, 189, 201, 202, 203, 205, 207
OFFSET
1,1
COMMENTS
The corresponding primes are in A144131.
Sequence is infinite under Bunyakovsky's conjecture. - Charles R Greathouse IV, May 29 2013
LINKS
MAPLE
filter:= n -> isprime(8*n^4 - 8*n^2+1):
select(filter, [$1..300]); # Robert Israel, Jan 22 2020
MATHEMATICA
lst={}; Do[If[PrimeQ[ChebyshevT [4, n]], AppendTo[lst, n]], {n, 10^3}]; lst
PROG
(PARI) is(n)=isprime(polchebyshev(4, 1, n)) \\ Charles R Greathouse IV, May 29 2013
CROSSREFS
Cf. A144131.
Sequence in context: A325548 A094568 A251607 * A183871 A211542 A368052
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 17 2012
STATUS
approved