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A004842
Numbers that are the sum of at most 2 positive 5th powers.
5
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
OFFSET
1,3
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 159 terms from Vincenzo 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: A357176 A018802 A166487 * A022378 A306950 A193419
KEYWORD
nonn,easy
STATUS
approved