A344729 Numbers that are the sum of three fourth powers in seven or more ways.

779888018, 5745705602, 8185089458, 11054952818, 12478208288, 14355295682, 21789116258, 22247419922, 26839201298, 29428835618, 31861462178, 33038379458, 37314202562, 38214512882, 41923075922, 46543615202, 49511121842, 51711350418, 54438780578, 56255300738, 59223741122, 62862779042, 63170929458, 63429959138, 71035097042, 71447292098, 73526154338, 73665805122, 81629817458

Offset

1,1

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..100

Example

779888018 is a term because 779888018 = 3^4+ 139^4+ 142^4 = 9^4+ 38^4+ 167^4 = 14^4+ 133^4+ 147^4 = 43^4+ 114^4+ 157^4 = 47^4+ 111^4+ 158^4 = 63^4+ 98^4+ 161^4 = 73^4+ 89^4+ 162^4

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, 3):
    tot = sum(pos)
    keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 7])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A344647, A344730, A344737, A344922, A345086.

Sequence in context: A157788 A058420 A297867 * A344730 A225389 A166121

Adjacent sequences: A344726 A344727 A344728 * A344730 A344731 A344732

Keyword

nonn

Author

David Consiglio, Jr., May 27 2021

Status

approved