Cyclotomic polynomials at x=-13.

Terms

a(0) =-13a(1) =-14a(2) =-12a(3) =157a(4) =170a(5) =26521a(6) =183a(7) =4482037a(8) =28562a(9) =4824613a(10) =30941a(11) =128011456717a(12) =28393a(14) =5229043a(15) =878077201a(16) =815730722a(18) =4829007a(20) =810932305