OFFSET
1,1
COMMENTS
Previous name was: Orders of cyclotomic polynomials containing a coefficient with an absolute value greater than one.
From David A. Corneth, Apr 21 2018: (Start)
Terms are composite.
If k is a term of the sequence then so is k * m for m > 0.
Let a primitive term p of this sequence be a term of which no divisor is in the sequence. Then p is an odd squarefree number. (End)
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..1627
MAPLE
isA013590 := proc(n)
numtheory[cyclotomic](n, x) ;
{coeffs(%, x)} ;
map(abs, %) ;
if % minus {1} = {} then
false;
else
true;
end if;
end proc:
for n from 1 do
if isA013590(n) then
print(n);
end if;
end do: # R. J. Mathar, Nov 28 2016
MATHEMATICA
S[ n_ ] := For[ j=1; t=0, j<n, j++, t=Cases[ CoefficientList[ Cyclotomic[ j, x ], x ], k_ /; Abs[ k ]>1 ]; If[ Length[ t ]!=0, Print[ j ] ] ]; S[ 856 ]
f[n_] := Max@ Abs@ CoefficientList[ Cyclotomic[n, x], x]; Select[ Range@ 1000, f@# > 1 &] (* Robert G. Wilson v *)
Select[Range[900], Max[Abs[CoefficientList[Cyclotomic[#, x], x]]]>1&] (* Harvey P. Dale, Mar 13 2013 *)
PROG
(PARI) is(n)=for(k=0, n, if(abs(polcoeff(polcyclo(n), k))>1, return(n))); 0
for(n=1, 1000, if(is(n), print1(n, ", "))) \\ Derek Orr, Apr 22 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter T. Wang (peterw(AT)cco.caltech.edu)
EXTENSIONS
Definition clarified by Harvey P. Dale, Mar 13 2013
New name from Michel Marcus, Apr 29 2018
STATUS
approved