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Numbers of the form 4^x + y^4 with x, y >= 0.
2

%I #15 Dec 01 2014 10:53:57

%S 1,2,4,5,16,17,20,32,64,65,80,82,85,97,145,256,257,260,272,320,337,

%T 512,626,629,641,689,881,1024,1025,1040,1105,1280,1297,1300,1312,1360,

%U 1552,1649,2320,2402,2405,2417,2465,2657,3425,4096,4097,4100

%N Numbers of the form 4^x + y^4 with x, y >= 0.

%C No terms are divisible by 3, 7 or 11.

%C Subsequence of A001481 and A250482.

%e 17 is in this sequence because 4^0+2^4 = 4^2+1^4=17.

%e 82 is in this sequence because 4^0+3^4 = 82.

%t nn=10; Union[Select[Flatten[Table[4^x + y^4, {x, 0, nn}, {y, 0, nn}]], #<=nn^4 &]]

%Y Cf. A001481, A002645.

%Y Cf. similar sequences listed in A250482.

%K nonn,less

%O 1,2

%A _Vincenzo Librandi_, Nov 26 2014