login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A004842 Numbers that are the sum of at most 2 positive 5th powers. 3
0, 1, 2, 32, 33, 64, 243, 244, 275, 486, 1024, 1025, 1056, 1267, 2048, 3125, 3126, 3157, 3368, 4149, 6250, 7776, 7777, 7808, 8019, 8800, 10901, 15552, 16807, 16808, 16839, 17050, 17831, 19932, 24583, 32768, 32769, 32800, 33011, 33614, 33792, 35893, 40544 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Vincenzo Librandi and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 159 terms from Librandi)

FORMULA

a(n) << n^(5/2). - Charles R Greathouse IV, Nov 30 2014

MATHEMATICA

Select[Table[n, {n, 0, 50000}], Length[PowersRepresentations[#, 2, 5]] > 0 &] (* Vladimir Joseph Stephan Orlovsky, Jul 19 2011 *)

PROG

(PARI) T=thueinit('z^5+1); is(n)=n==0 || #select(v->min(v[1], v[2])>=0, thue(T, n))>0 \\ Charles R Greathouse IV, Nov 30 2014

(PARI) is(n)=for(m=sqrtnint(n\2, 5), sqrtnint(n, 5), if(ispower(n-m^5, 5), return(1))); 0 \\ Charles R Greathouse IV, Nov 30 2014

(PARI) list(lim)=my(v=List(), n5); for(n=0, sqrtnint(lim\=1, 5), n5=n^5; for(m=0, min(sqrtnint(lim-n5, 5), n), listput(v, n5+m^5))); Set(v) \\ Charles R Greathouse IV, Nov 30 2014

CROSSREFS

Cf. A004845.

Sequence in context: A030001 A018802 A166487 * A022378 A193419 A160557

Adjacent sequences:  A004839 A004840 A004841 * A004843 A004844 A004845

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified March 23 01:23 EDT 2017. Contains 283901 sequences.