A345084 Numbers that are the sum of three third powers in exactly six ways.

1296378, 1371735, 1409400, 1614185, 1824040, 1885248, 2101464, 2302028, 2305395, 2542968, 2851848, 2889216, 2974392, 2988441, 3185792, 3380833, 3681280, 3689496, 3706984, 3775680, 3906657, 4109832, 4123008, 4142683, 4422592, 4842872, 4952312, 5005125, 5023656

Offset

1,1

Comments

Differs from A345083 at term 7 because 2016496 = 5^3 + 71^3 + 117^3 = 9^3 + 65^3 + 119^3 = 18^3 + 20^3 + 125^3 = 46^3 + 96^3 + 99^3 = 53^3 + 59^3 + 117^3 = 65^3 + 89^3 + 99^3 = 82^3 + 84^3 + 93^3.

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..1000

Example

1296378 is a term because 1296378 = 3^3 + 75^3 + 94^3  = 8^3 + 32^3 + 107^3  = 20^3 + 76^3 + 93^3  = 30^3 + 58^3 + 101^3  = 32^3 + 80^3 + 89^3  = 59^3 + 74^3 + 86^3.

Prog

(Python)
from itertools import combinations_with_replacement as cwr
from collections import defaultdict
keep = defaultdict(lambda: 0)
power_terms = [x**3 for x in range(1, 1000)]
for pos in cwr(power_terms, 3):
    tot = sum(pos)
    keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v == 6])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A025326, A343970, A344648, A345083, A345085, A345149.

Sequence in context: A354560 A185776 A345083 * A262531 A250830 A258535

Adjacent sequences: A345081 A345082 A345083 * A345085 A345086 A345087

Keyword

nonn

Author

David Consiglio, Jr., Jun 07 2021

Status

approved