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

1,1

Links

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

Example

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)

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 *)

Crossrefs

Cf. A001015 (seventh powers).

Column k=7 of A336725.

Sequence in context: A229464 A317216 A119670 * A001533 A143181 A183478

Adjacent sequences: A003371 A003372 A003373 * A003375 A003376 A003377

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved