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A004881 Numbers that are the sum of at most 8 nonzero 8th powers. 1
0, 1, 2, 3, 4, 5, 6, 7, 8, 256, 257, 258, 259, 260, 261, 262, 263, 512, 513, 514, 515, 516, 517, 518, 768, 769, 770, 771, 772, 773, 1024, 1025, 1026, 1027, 1028, 1280, 1281, 1282, 1283, 1536, 1537, 1538, 1792, 1793, 2048, 6561, 6562, 6563, 6564, 6565, 6566 (list; graph; refs; listen; history; text; internal format)
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^8<=n and b(n-i^8, 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, 8), 8) do od; k

    end:

seq(a(n), n=1..60);  # 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^8 <= n && b[n - i^8, i, t - 1]);

a[n_] := a[n] = (For[k = 1 + If[n == 1, -1, a[n - 1]], !b[k, k^(1/8) // Floor, 8], k++]; k);

Array[a, 60] (* Jean-Fran├žois Alcover, Apr 06 2017, after Alois P. Heinz *)

CROSSREFS

Sequence in context: A037443 A073790 A029965 * A004892 A004903 A004914

Adjacent sequences:  A004878 A004879 A004880 * A004882 A004883 A004884

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Alois P. Heinz, Sep 16 2016

STATUS

approved

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Last modified May 30 12:03 EDT 2020. Contains 334724 sequences. (Running on oeis4.)