A003398 Numbers that are the sum of 9 positive 9th powers.

9, 520, 1031, 1542, 2053, 2564, 3075, 3586, 4097, 4608, 19691, 20202, 20713, 21224, 21735, 22246, 22757, 23268, 23779, 39373, 39884, 40395, 40906, 41417, 41928, 42439, 42950, 59055, 59566, 60077, 60588, 61099, 61610, 62121, 78737, 79248, 79759, 80270, 80781, 81292, 98419

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

From David A. Corneth, Aug 02 2020: (Start)
26015282 is in the sequence as 26015282 = 1^9 + 1^9 + 1^9 + 2^9 + 5^9 + 5^9 + 5^9 + 6^9 + 6^9.
56248367 is in the sequence as 56248367 = 2^9 + 5^9 + 5^9 + 5^9 + 6^9 + 6^9 + 6^9 + 6^9 + 6^9.
84613980 is in the sequence as 84613980 = 1^9 + 1^9 + 1^9 + 1^9 + 2^9 + 5^9 + 5^9 + 7^9 + 7^9. (End)

Mathematica

M = 10^5; m = M^(1/9) // Ceiling; Reap[
For[a = 1, a <= m, a++,
For[b = a, b <= m, b++, For[c = b, c <= m, c++, For[d = c, d <= m, d++,
For[e = d, e <= m, e++, For[f = e, f <= m, f++, For[g = f, g <= m, g++,
For[h = g, h <= m, h++, For[i = h, i <= m, i++,
s = a^9 + b^9 + c^9 + d^9 + e^9 + f^9 + g^9 + h^9 + i^9;
If[s <= M, Sow[s]]]]]]]]]]]][[2, 1]] // Union (* Jean-François Alcover, Dec 01 2020 *)

Crossrefs

Cf. A001017 (9th powers).

Column k=9 of A336725.

Sequence in context: A230671 A281443 A367446 * A015508 A281800 A381752

Adjacent sequences: A003395 A003396 A003397 * A003399 A003400 A003401

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved