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Numbers that are the sum of a square s and a fourth power t such that 0 < s < t.
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%I #6 Feb 01 2021 18:07:29

%S 17,20,25,82,85,90,97,106,117,130,145,257,260,265,272,281,292,305,320,

%T 337,356,377,400,425,452,481,626,629,634,641,650,661,674,689,706,725,

%U 746,769,794,821,850,881,914,949,986,1025,1066,1109,1154,1201,1297,1300,1305,1312

%N Numbers that are the sum of a square s and a fourth power t such that 0 < s < t.

%e 20 is in the sequence since 2^2 + 2^4 = 4 + 16 = 20, where 0 < 4 < 16.

%t Table[If[Sum[(Floor[i^(1/2)] - Floor[(i - 1)^(1/2)]) (Floor[(n - i)^(1/4)] - Floor[(n - i - 1)^(1/4)]), {i, Floor[(n - 1)/2]}] > 0, n, {}], {n, 1500}] // Flatten

%Y Cf. A010052.

%K nonn

%O 1,1

%A _Wesley Ivan Hurt_, Dec 26 2020