A003374 Numbers that are the sum of 7 positive 7th powers.

7, 134, 261, 388, 515, 642, 769, 896, 2193, 2320, 2447, 2574, 2701, 2828, 2955, 4379, 4506, 4633, 4760, 4887, 5014, 6565, 6692, 6819, 6946, 7073, 8751, 8878, 9005, 9132, 10937, 11064, 11191, 13123, 13250, 15309, 16390, 16517, 16644, 16771, 16898, 17025, 17152, 18576

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Examples

			From _David A. Corneth_, Aug 03 2020: (Start)
2200409 is in the sequence as 2200409 = 3^7 + 3^7 + 3^7 + 3^7 + 4^7 + 5^7 + 8^7.
4122089 is in the sequence as 4122089 = 3^7 + 3^7 + 7^7 + 7^7 + 7^7 + 7^7 + 7^7.
6356992 is in the sequence as 6356992 = 4^7 + 4^7 + 4^7 + 4^7 + 8^7 + 8^7 + 8^7. (End)
		

Links

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

Crossrefs

Cf. A001015 (seventh powers).

Column k=7 of A336725.

Programs

Mathematica

M = 21027478; m = M^(1/7) // 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++,
s = a^7 + b^7 + c^7 + d^7 + e^7 + f^7 + g^7;
If[s <= M, Sow[s]]]]]]]]]][[2, 1]] // Union (* Jean-François Alcover, Dec 01 2020 *)