A123035 Prime sums of 6 positive 5th powers.

37, 521, 1091, 1153, 1997, 2083, 2239, 3137, 3559, 4129, 4153, 4457, 4637, 5449, 6199, 7253, 8147, 8573, 9319, 9323, 10069, 10463, 11959, 14029, 15083, 15649, 16649, 16843, 16883, 17327, 17389, 17569, 17959, 18077, 18773, 18803, 19373, 20029

Offset: 1

Author

Jonathan Vos Post, Sep 24 2006

Keywords

• nonn

Comments

Primes in the sumset {A000584 + A000584 + A000584 + A000584 + A000584 + A000584}.

There must be an odd number of odd terms in the sum, either one even and 5 odd terms (as with 37 = 1^5 + 1^5 + 1^5 + 1^5 + 1^5 + 2^5 and 521 = 1^5 + 1^5 + 1^5 + 2^5 + 3^5 + 3^5), three even and 3 odd terms (as with 1091 = 1^5 + 1^5 + 1^5 + 2^5 + 2^5 + 4^5) or five even terms and one odd term (as with 1^5 + 2^5 + 2^5 + 2^5 + 2^5 + 4^5). The sum of two positive 5th powers (A003347), other than 2 = 1^5 + 1^5, cannot be prime.

Examples

			a(1) = 37 = 1^5 + 1^5 + 1^5 + 1^5 + 1^5 + 2^5.
a(2) = 521 = 1^5 + 1^5 + 1^5 + 2^5 + 3^5 + 3^5.
a(3) = 1091 = 1^5 + 1^5 + 1^5 + 2^5 + 2^5 + 4^5.
a(4) = 1153 = 1^5 + 2^5 + 2^5 + 2^5 + 2^5 + 4^5.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A000584, A003336, A003347, A003349, A003350, A003351.

Programs

Mathematica

up = 10^6; q = Range[up^(1/5)]^5; a = {0}; Do[b = Select[ Union@ Flatten@Table[e + a, {e, q}], # <= up &]; a = b, {k, 6}]; Select[a, PrimeQ] (* Giovanni Resta, Jun 13 2016 *)

Formula

A000040 INTERSECTION A003351.

Extensions

More terms from Max Alekseyev, Sep 24 2011