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A344729
Numbers that are the sum of three fourth powers in seven or more ways.
6
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
KEYWORD
nonn
AUTHOR
STATUS
approved