A345577 Numbers that are the sum of eight fourth powers in two or more ways.

263, 278, 293, 308, 323, 343, 358, 373, 388, 423, 438, 453, 503, 518, 533, 548, 563, 583, 598, 613, 628, 678, 693, 758, 773, 788, 803, 853, 868, 887, 902, 917, 932, 933, 967, 982, 997, 1028, 1043, 1047, 1062, 1108, 1127, 1142, 1157, 1172, 1222, 1237, 1283

Offset

1,1

Links

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

Example

278 is a term because 278 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 4^4 = 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, 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. A003342, A345532, A345568, A345578, A345586, A345610, A345834.

Sequence in context: A224556 A052033 A105008 * A345834 A180556 A288502

Adjacent sequences: A345574 A345575 A345576 * A345578 A345579 A345580

Keyword

nonn

Author

David Consiglio, Jr., Jun 20 2021

Status

approved