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.

A190581 Value of z in the Diophantine equation x^3 + y^3 = n*z^3 (with x>0 and minimal and x >= y and y != 0).

Original entry on oeis.org

1, 21, 1, 1, 39, 3, 294, 7, 1, 7, 9954, 1, 1, 57, 42, 582, 182, 1, 1, 129, 2, 3, 6111, 197028, 217, 7083, 1, 3, 1, 1, 1323, 620505, 3318, 13, 43, 3606, 1302, 3, 111, 330498, 3, 216266610, 13, 273, 1, 5733, 590736058375050, 3, 1, 117, 1014, 25767, 19, 37, 1878, 1029364, 1, 37045412880, 1, 1, 1, 11285694
Offset: 1

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Author

Jean-François Alcover, May 13 2011

Keywords

Comments

A190356(n)^3 + y^3 = A020898(n)*a(n)^3. Unknown y corresponds to sequence A190580.
The 4 sequences A020898 [i.e. n], A190356 [i.e. x], A190580 [i.e. y] and A190581 [i.e. z] satisfy the equation A190356(n)^3 + A190580(n)^3 = A020898(n) * A190581(n)^3

Examples

			a(18) = 1  because  A020898(18) = 35 and 3^3 + 2^3 = 35*1^3.
		

Crossrefs

Programs

  • Mathematica
    a[n_] := z /. ToRules[ Reduce[ z > 0 && A190356[[n]]^3 + A190580[[n]]^3 == A020898[[n]]*z^3, z, Integers]]; Table[a[n] , {n, 1, 62}]