A344647 Numbers that are the sum of three fourth powers in six or more ways.

292965218, 779888018, 1010431058, 1110995522, 1500533762, 1665914642, 2158376402, 2373191618, 2636686962, 2689817858, 3019732898, 3205282178, 3642994082, 3831800882, 4324686002, 4687443488, 5064808658, 5175310322, 5745705602, 6317554418, 6450435362, 6720346178, 7018992162

Offset

1,1

Links

Sean A. Irvine, Table of n, a(n) for n = 1..10000 (terms 1..70 from David Consiglio, Jr.)

Example

1010431058 is a term because 1010431058 = 13^4 + 143^4 + 156^4 = 31^4 + 132^4 + 163^4 = 44^4 + 123^4 + 167^4 = 52^4 + 117^4 + 169^4 = 69^4 + 103^4 + 172^4 = 81^4 + 92^4 + 173^4

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, 500)]
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. A344364, A344648, A344729, A344904, A345083.

Sequence in context: A234807 A204055 A344364 * A344648 A251566 A112452

Adjacent sequences: A344644 A344645 A344646 * A344648 A344649 A344650

Keyword

nonn

Author

David Consiglio, Jr., May 25 2021

Status

approved