OFFSET
1,1
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)
Eric Weisstein's World of Mathematics, Biquadratic Number.
EXAMPLE
From David A. Corneth, Aug 04 2020: (Start)
13090 is in the sequence as 13090 = 4^4 + 4^4 + 5^4 + 6^4 + 8^4 + 9^4.
17539 is in the sequence as 17539 = 2^4 + 3^4 + 4^4 + 5^4 + 9^4 + 10^4.
23732 is in the sequence as 23732 = 3^4 + 5^4 + 5^4 + 7^4 + 10^4 + 10^4. (End)
MATHEMATICA
Select[Range[1000], AnyTrue[PowersRepresentations[#, 6, 4], First[#]>0&]&] (* Jean-François Alcover, Jul 18 2017 *)
PROG
(Python)
from itertools import combinations_with_replacement as combs_with_rep
def aupto(limit):
qd = [k**4 for k in range(1, int(limit**.25)+2) if k**4 + 5 <= limit]
ss = set(sum(c) for c in combs_with_rep(qd, 6))
return sorted(s for s in ss if s <= limit)
print(aupto(700)) # Michael S. Branicky, Jun 21 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved