The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A231612 Numbers n such that the four fourth-degree cyclotomic polynomials are simultaneously prime. 4
 2, 90750, 194468, 229592, 388332, 868592, 1054868, 1148390, 1380380, 1415920, 1461372, 1496010, 1614800, 1706398, 1992210, 2439042, 2478212, 2644498, 2791910, 3073300, 3264448, 3824370, 3892780, 3939222, 3941938, 4425970, 4468980, 4594138, 4683700 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The polynomials are cyclotomic(5,x) = 1 + x + x^2 + x^3 + x^4, cyclotomic(8,x) = 1 + x^4, cyclotomic(10,x) = 1 - x + x^2 - x^3 + x^4, and cyclotomic(12,x) = 1 - x^2 + x^4. The numbers 5, 8, 10, and 12 are in the fourth row of A032447. By Schinzel's hypothesis H, there are an infinite number of n that yield simultaneous primes. Note that the two first-degree cyclotomic polynomials, x-1 and x+1, yield the twin primes for the numbers in A014574. REFERENCES See A087277. LINKS Table of n, a(n) for n=1..29. MATHEMATICA Select[Range[5000000], PrimeQ[Cyclotomic[5, #]] && PrimeQ[Cyclotomic[8, #]] && PrimeQ[Cyclotomic[10, #]] && PrimeQ[Cyclotomic[12, #]] &] Select[Range[47*10^5], AllTrue[Thread[Cyclotomic[{5, 8, 10, 12}, #]], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 22 2018 *) CROSSREFS Cf. A014574 (first degree solutions: average of twin primes). Cf. A087277 (similar, but with second-degree cyclotomic polynomials). Cf. A231613 (similar, but with sixth-degree cyclotomic polynomials). Cf. A231614 (similar, but with eighth-degree cyclotomic polynomials). Sequence in context: A371645 A060069 A354177 * A296104 A170995 A319022 Adjacent sequences: A231609 A231610 A231611 * A231613 A231614 A231615 KEYWORD nonn AUTHOR T. D. Noe, Dec 11 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 19 00:35 EDT 2024. Contains 372666 sequences. (Running on oeis4.)