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A154430 Odd squarefree numbers n such that the cyclotomic polynomial Phi(n,x) has height > 1. 7
105, 165, 195, 255, 273, 285, 345, 357, 385, 429, 455, 555, 561, 595, 609, 615, 627, 645, 665, 705, 715, 759, 777, 795, 805, 897, 935, 957, 969, 987, 1001, 1005, 1015, 1023, 1045, 1065, 1085, 1095, 1105, 1131, 1155, 1185, 1221, 1235, 1239, 1245, 1265 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The height of a polynomial is the maximum of the absolute value of its coefficients. Different from A118678, which excludes terms that are a multiple of smaller terms.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Range[2000], OddQ[#] && SquareFreeQ[#] && Max[ Abs[ CoefficientList[ Cyclotomic[#, x], x]]] > 1&] (* Jean-Fran├žois Alcover, Nov 14 2016 *)

PROG

(PARI) is(n)=issquarefree(n) && n%2 && vecmax(abs(Vec(polcyclo(n))))>1 \\ Charles R Greathouse IV, Nov 05 2017

CROSSREFS

Cf. A013590, A117318, A117223, A152940, A152941, A152942, A152943, A152955.

Sequence in context: A216918 A278569 A046389 * A118678 A152940 A189936

Adjacent sequences:  A154427 A154428 A154429 * A154431 A154432 A154433

KEYWORD

nonn

AUTHOR

T. D. Noe, Jan 09 2009

STATUS

approved

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Last modified May 26 02:35 EDT 2019. Contains 323579 sequences. (Running on oeis4.)