A345586 Numbers that are the sum of nine fourth powers in two or more ways.

264, 279, 294, 309, 324, 339, 344, 359, 374, 389, 404, 424, 439, 454, 469, 504, 519, 534, 549, 564, 579, 584, 599, 614, 629, 644, 664, 679, 694, 709, 759, 774, 789, 804, 819, 839, 854, 869, 884, 888, 903, 918, 933, 934, 948, 949, 968, 983, 998, 1013, 1014

Offset

1,1

Links

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

Example

279 is a term because 279 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 4^4 = 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 2^4 + 3^4 + 3^4 + 3^4.

Prog

(Python)
from itertools import combinations_with_replacement as cwr
from collections import defaultdict
keep = defaultdict(lambda: 0)
power_terms = [x**4 for x in range(1, 1000)]
for pos in cwr(power_terms, 9):
    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. A003343, A345541, A345577, A345587, A345595, A345619, A345844.

Sequence in context: A266036 A157828 A065570 * A345844 A253694 A253701

Adjacent sequences: A345583 A345584 A345585 * A345587 A345588 A345589

Keyword

nonn

Author

David Consiglio, Jr., Jun 20 2021

Status

approved