A345556 Numbers that are the sum of ten cubes in eight or more ways.

623, 625, 630, 632, 644, 651, 658, 662, 665, 677, 684, 688, 695, 697, 699, 708, 714, 715, 721, 723, 725, 728, 730, 733, 734, 736, 740, 745, 747, 749, 751, 752, 754, 756, 757, 758, 759, 760, 764, 766, 769, 771, 773, 775, 776, 777, 778, 780, 782, 785, 786, 787

Offset

1,1

Links

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

Example

625 is a term because 625 = 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 3^3 + 3^3 + 3^3 + 3^3 + 7^3 = 1^3 + 1^3 + 1^3 + 1^3 + 3^3 + 3^3 + 3^3 + 4^3 + 4^3 + 5^3 = 1^3 + 1^3 + 1^3 + 2^3 + 3^3 + 3^3 + 3^3 + 3^3 + 5^3 + 5^3 = 1^3 + 1^3 + 2^3 + 2^3 + 2^3 + 2^3 + 4^3 + 4^3 + 4^3 + 5^3 = 1^3 + 1^3 + 2^3 + 2^3 + 2^3 + 3^3 + 3^3 + 3^3 + 3^3 + 6^3 = 1^3 + 2^3 + 2^3 + 2^3 + 2^3 + 2^3 + 3^3 + 4^3 + 5^3 + 5^3 = 1^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 4^3 + 4^3 = 2^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 3^3 + 5^3.

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, 10):
    tot = sum(pos)
    keep[tot] += 1
    rets = sorted([k for k, v in keep.items() if v >= 8])
    for x in range(len(rets)):
        print(rets[x])

Crossrefs

Cf. A345547, A345555, A345557, A345601, A345810, A346807.

Sequence in context: A268018 A321675 A371695 * A345810 A330932 A255086

Adjacent sequences: A345553 A345554 A345555 * A345557 A345558 A345559

Keyword

nonn

Author

David Consiglio, Jr., Jun 20 2021

Status

approved