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

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Examples

			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)
		

Links

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

Crossrefs

Cf. A001017 (9th powers).

Column k=9 of A336725.

Programs

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 *)