cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A135064 Numbers n such that the quintic polynomial x^5 - 10*n*x^2 - 24*n has Galois group A_5 over rationals.

Original entry on oeis.org

1, 11, 29, 76, 199, 521, 1364, 3571, 9349, 24476, 64079, 167761, 439204, 1149851, 3010349, 7881196, 20633239, 54018521, 141422324, 370248451, 969323029, 2537720636, 6643838879, 17393796001, 45537549124, 119218851371, 312119004989, 817138163596, 2139295485799, 5600748293801
Offset: 1

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Author

Artur Jasinski, Nov 15 2007

Keywords

Comments

Sequence appears to agree with the Lucas bisection A002878 for n > 1. - Klaus Brockhaus, Nov 18 2007
A002878(n) is in this sequence for all 1 < n <= 1000, and the sequences agree through a(20) = 370248451. Of course this is not a proof. - Charles R Greathouse IV, Mar 03 2017, updated Mar 20 2017
If this agreement is provable then of course it provides recurrences, generating functions, etc., for this sequence. - N. J. A. Sloane, Nov 24 2007 However, at present this is only a conjecture, and should not be used as the basis for formulas or computer programs. - N. J. A. Sloane, Mar 04 2017
Comparing A135064 with A002878, the number 4 is missing. In this case the Galois group of the quintic polynomial x^5 - 40*x^2 - 96 is dihedral of order 10. - Artur Jasinski, May 27 2010
The relation with A002878 is proved in Wong's article. - Eric M. Schmidt, Nov 25 2017

Crossrefs

Programs

  • PARI
    is(n)=my(p=Pol([1,0,0,-10*n,0,-24*n])); polisirreducible(p) && polgalois(p)[1]==60 \\ Charles R Greathouse IV, Mar 03 2017

Extensions

a(20) corrected by Klaus Brockhaus, Nov 18 2007
Unjustified formulas, programs, and b-file deleted. - N. J. A. Sloane, Mar 04 2017