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A371554 Consider primitive pairs of integers (b, c) with b > 0 such that x^5 + b*x + c = 0 is irreducible and solvable by radicals: sequence gives values of c. 4

%I #13 Apr 20 2024 16:36:16

%S 44,12,44,32,64,1344,576,1344,832,275,4170,2375,3750,4060,128700,

%T 13243,1510620,24000,3348800,8788,467961,51072,133440,474214,61500,

%U 128700,85683,514098,509197,199927,24000,3720000,21376538,210990,486343,114244,12681084

%N Consider primitive pairs of integers (b, c) with b > 0 such that x^5 + b*x + c = 0 is irreducible and solvable by radicals: sequence gives values of c.

%C See A371553.

%H Ben Whitmore, <a href="/A371554/b371554.txt">Table of n, a(n) for n = 1..95</a>

%F x^5 + A371553(n)*x + a(n) is irreducible and solvable by radicals.

%e a(1) = 44 because A371553(1) = 11, and x^5 + 11*x + 44 is irreducible and solvable by radicals, and (11, 44) is a primitive pair.

%t pairs = Join @@ Table[

%t Select[{m, Abs[#1 - b] #2/5} & @@@

%t Sort[SolveValues[x^2 - (6b + 5y^4)x + 25b^2 == 0 && y > 0, {x, y},

%t Integers]],

%t Max[Last /@ FactorInteger[GCD @@ #]] < 4 &&

%t AllTrue[#, IntegerQ] &&

%t IrreduciblePolynomialQ[x^5 + #1x + #2 & @@ #] &

%t ],

%t {b, 1, 1000}

%t ];

%t pairs[[All, 2]]

%Y For values of b see A371553.

%K nonn

%O 1,1

%A _Ben Whitmore_, Mar 27 2024

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Last modified August 9 11:50 EDT 2024. Contains 375042 sequences. (Running on oeis4.)