The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 Table of n, a(n) for n=1..23. 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 Cf. A001014, A001015, A000404, A009003, A050801. Sequence in context: A302271 A301847 A302970 * A302074 A302813 A303474 Adjacent sequences: A291829 A291830 A291831 * A291833 A291834 A291835 KEYWORD nonn AUTHOR XU Pingya, Sep 03 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

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