A126657 Prime numbers that are the sum of three distinct positive fourth powers.

353, 1553, 5393, 6833, 7187, 7793, 7873, 8963, 9043, 9587, 10337, 11953, 13697, 14177, 14723, 16193, 17123, 20753, 21283, 21377, 21617, 23603, 25457, 28643, 29873, 30113, 30817, 31393, 35393, 35747, 39857, 43283, 45233, 45377, 46273

Offset: 1

Author

Tomas Xordan, Feb 09 2007

Keywords

• nonn

Examples

			1553= 1^4 + 4^4 + 6^4 = 1 + 256 + 1296.
6833 = 2^4 + 4^4 + 9^4 = 16 + 256 + 6561.
21377 = 2^4 + 5^4 + 12^4 = 16 + 625 + 20736.
35747 = 5^4 + 9^4 + 13^4 = 625 + 6561 + 28561.
		

Crossrefs

Cf. A125516, A126658.

Programs

Mathematica

Union[Select[Total/@Subsets[Range[20]^4,{3}],PrimeQ]] (* Harvey P. Dale, May 08 2012 *)

PARI

{m=15;p=m^4;v=vector(m,x,x^4);w=[];for(i=1,m-2,for(j=i+1,m-1, for(k=j+1,m,if((n=v[i]+v[j]+v[k])
				

Extensions

Edited, corrected and extended by Klaus Brockhaus, Feb 11 2007