OFFSET
1,1
COMMENTS
When a^7 + b^7 = m, (ma)^7 + (mb)^7 = m^8 is 4th power.
When k in this sequence, k*(n^7) (n = 2, 3, ... ) is also in this sequence.
EXAMPLE
4^4 = 2^7 + 2^7, so 4 is in the sequence.
16641^4 = 129^7 + 358^7, so 16641 is in the sequence.
MATHEMATICA
lst={}; Do[If[IntegerQ[(n^4-a^7)^(1/7)], AppendTo[lst, n]], {n, 1.4*10^9}, {a, (n^4/2)^(1/7)}]; lst
CROSSREFS
KEYWORD
nonn
AUTHOR
XU Pingya, Sep 03 2017
STATUS
approved