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A291832 Numbers k such that k^6 is sum of two positive 7th powers. 0
64, 8192, 139968, 1048576, 5000000, 17915904, 52706752, 134217728, 306110016, 640000000, 1247178944, 2293235712, 4015905088, 6746464256, 10935000000, 17179869184, 26261675072, 39182082048, 57207791296, 81920000000, 115269666624, 159638904832, 217908828608 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
When a^7 + b^7 = m, (m^5*a)^7 + (m^5*b)^7 = m^36 is 6th power.
When k in this sequence, k*(n^7) (n = 2, 3, ... ) is also in this sequence.
LINKS
EXAMPLE
64^6 = 32^7 + 32^7, so 64 is in the sequence.
(5000000)^6 = (500000)^7 + (500000)^7, so 5000000 is in the sequence.
MATHEMATICA
lst={}; Do[If[IntegerQ[(n^6-a^7)^(1/7)], AppendTo[lst, n]], {n, 2.9*10^11}, {a, (n^6/2)^(1/7)}]; lst
CROSSREFS
Sequence in context: A302271 A301847 A302970 * A302074 A302813 A303474
KEYWORD
nonn
AUTHOR
XU Pingya, Sep 03 2017
STATUS
approved

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Last modified July 24 13:53 EDT 2024. Contains 374584 sequences. (Running on oeis4.)