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.

A123034 Prime sums of 5 positive 5th powers.

Original entry on oeis.org

5, 67, 1301, 1543, 2113, 2293, 2777, 3191, 3253, 3347, 3371, 3433, 3613, 4339, 5237, 5417, 5659, 6229, 6737, 7307, 7549, 7873, 8053, 8537, 8803, 9377, 9439, 9619, 9857, 10099, 11177, 11423, 11927, 12743, 15797, 15859, 16811, 17053, 17183, 18679, 18919, 19163
Offset: 1

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Author

Jonathan Vos Post, Sep 24 2006

Keywords

Comments

Primes in the sumset {A000584 + A000584 + A000584 + A000584 + A000584}.
There must be an odd number of odd terms in the sum, either 5 odd terms (as with 5 = 1^5 + 1^5 + 1^5 + 1^5 + 1^5 and 16811 = 1^5 + 1^5 + 1^5 + 1^5 + 7^5), two even and 3 odd terms (as with 67 = 1^5 + 1^5 + 1^5 + 2^5 + 2^5 and 1301 = 1^5 + 1^5 + 2^5 + 3^5 + 4^5) or four even terms and one odd term (as with 3253 = 2^5 + 2^5 + 2^5 + 2^5 + 5^5). The sum of two positive 5th powers (A003347), other than 2 = 1^5 + 1^5, cannot be prime.

Examples

			a(1) = 5 = 1^5 + 1^5 + 1^5 + 1^5 + 1^5.
a(2) = 67 = 1^5 + 1^5 + 1^5 + 2^5 + 2^5.
a(3) = 1301 = 1^5 + 1^5 + 2^5 + 3^5 + 4^5.
a(4) = 1543 = 1^5 + 2^5 + 3^5 + 3^5 + 4^5.
a(5) = 2113 = 1^5 + 2^5 + 2^5 + 4^5 + 4^5.
a(6) = 3191 = 1^5 + 1^5 + 2^5 + 2^5 + 5^5.
a(7) = 4339 = 3^5 + 4^5 + 4^5 + 4^5 + 4^5.
		

Crossrefs

Programs

  • Mathematica
    Take[Select[Union[Total/@Tuples[Range[10]^5,5]],PrimeQ],60] (* Harvey P. Dale, Jul 21 2014 *)

Formula

A000040 INTERSECTION A003350.

Extensions

Corrected and extended by Harvey P. Dale, Jul 21 2014