A004844 Numbers that are the sum of at most 4 positive 5th powers.

0, 1, 2, 3, 4, 32, 33, 34, 35, 64, 65, 66, 96, 97, 128, 243, 244, 245, 246, 275, 276, 277, 307, 308, 339, 486, 487, 488, 518, 519, 550, 729, 730, 761, 972, 1024, 1025, 1026, 1027, 1056, 1057, 1058, 1088, 1089, 1120, 1267, 1268, 1269, 1299, 1300, 1331, 1510, 1511

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Maple

b:= proc(n, i, t) option remember; n=0 or i>0 and t>0
      and (b(n, i-1, t) or i^5<=n and b(n-i^5, i, t-1))
    end:
a:= proc(n) option remember; local k;
      for k from 1+ `if`(n=1, -1, a(n-1))
      while not b(k, iroot(k, 5), 4) do od; k
    end:
seq(a(n), n=1..50);  # Alois P. Heinz, Sep 16 2016

Mathematica

b[n_, i_, t_] := b[n, i, t] = n==0 || i>0 && t>0 && (b[n, i-1, t] || i^5 <= n && b[n - i^5, i, t-1]);
a[n_] := a[n] = Module[{k}, For[k = 1+If[n==1, -1, a[n-1]], !b[k, Floor[ k^(1/5)], 4], k++]; k];
Array[a, 50] (* Jean-François Alcover, Nov 16 2020, after Alois P. Heinz *)

Crossrefs

Sequence in context: A250189 A255253 A076592 * A037324 A067242 A028354

Adjacent sequences: A004841 A004842 A004843 * A004845 A004846 A004847

Keyword

nonn

Author

N. J. A. Sloane

Status

approved