A342685 Numbers that are the sum of five fifth powers in two or more ways.

4097, 51446, 51477, 51688, 52469, 54570, 59221, 68252, 68905, 84213, 110494, 131104, 151445, 212496, 300277, 325174, 325713, 355114, 422135, 422738, 589269, 637418, 794434, 810820, 876734, 876765, 876976, 877757, 879858, 884509, 893540, 909501, 924912, 935782, 976733, 995571, 1037784, 1083457

Offset

1,1

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..20000

Example

51477 = 2^5 + 4^5 + 7^5 + 7^5 + 7^5
      = 2^5 + 5^5 + 6^5 + 6^5 + 8^5
so 51477 is a term.

Prog

(Python)
from itertools import combinations_with_replacement as cwr
from collections import defaultdict
keep = defaultdict(lambda: 0)
power_terms = [x**5 for x in range(1, 500)]
for pos in cwr(power_terms, 5):
    tot = sum(pos)
    keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 2])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A003350, A342686, A342687, A344238, A344644, A345507.

Sequence in context: A351311 A044887 A217196 * A342686 A321809 A017687

Adjacent sequences: A342682 A342683 A342684 * A342686 A342687 A342688

Keyword

nonn,changed

Author

David Consiglio, Jr., May 17 2021

Status

approved