A345532 Numbers that are the sum of eight cubes in two or more ways.

132, 139, 158, 160, 167, 174, 181, 186, 193, 195, 197, 200, 212, 216, 219, 223, 230, 237, 238, 244, 249, 251, 256, 258, 263, 265, 270, 272, 275, 277, 282, 284, 286, 288, 289, 291, 293, 296, 298, 300, 301, 303, 307, 308, 310, 312, 314, 315, 317, 319, 321, 322

Offset

1,1

Links

Sean A. Irvine, Table of n, a(n) for n = 1..10000

Example

139 is a term because 139 = 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 2^3 + 4^3 = 2^3 + 2^3 + 2^3 + 2^3 + 2^3 + 2^3 + 3^3 + 3^3.

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, 8):
    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. A003331, A345489, A345520, A345533, A345541, A345577, A345784.

Sequence in context: A105684 A211407 A108601 * A345784 A039603 A354812

Adjacent sequences: A345529 A345530 A345531 * A345533 A345534 A345535

Keyword

nonn

Author

David Consiglio, Jr., Jun 20 2021

Status

approved