OFFSET
1,1
LINKS
David Consiglio, Jr., Table of n, a(n) for n = 1..20000
EXAMPLE
6850 = 1^4 + 2^4 + 2^4 + 4^4 + 9^4
= 2^4 + 3^4 + 4^4 + 7^4 + 8^4
= 3^4 + 3^4 + 6^4 + 6^4 + 8^4
so 6850 is a term of this sequence.
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, 50)]
for pos in cwr(power_terms, 5):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 3])
for x in range(len(rets)):
print(rets[x])
CROSSREFS
KEYWORD
nonn
AUTHOR
David Consiglio, Jr., May 12 2021
STATUS
approved