A344644 Numbers that are the sum of four fifth powers in two or more ways.

51445, 876733, 1646240, 3558289, 4062500, 5687000, 7962869, 8227494, 9792364, 9924675, 10908544, 12501135, 15249850, 18317994, 18804544, 20611151, 20983875, 21297837, 23944908, 24201342, 24598407, 27806867, 28055456, 29480343, 31584102, 32557875, 32814683, 35469555, 40882844, 45177175

Offset

1,1

Links

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

Example

1646240 is a term because 1646240 = 9^5 + 15^5 + 15^5 + 15^5 = 11^5 + 13^5 + 13^5 + 17^5

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, 4):
    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. A003349, A309763, A342685, A344645, A345010, A345337.

Sequence in context: A076710 A203405 A152512 * A344645 A203354 A289823

Adjacent sequences: A344641 A344642 A344643 * A344645 A344646 A344647

Keyword

nonn

Author

David Consiglio, Jr., May 25 2021

Status

approved