A344647 - OEIS

%I #8 Jul 31 2021 18:29:15

%S 292965218,779888018,1010431058,1110995522,1500533762,1665914642,

%T 2158376402,2373191618,2636686962,2689817858,3019732898,3205282178,

%U 3642994082,3831800882,4324686002,4687443488,5064808658,5175310322,5745705602,6317554418,6450435362,6720346178,7018992162

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

%H Sean A. Irvine, <a href="/A344647/b344647.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..70 from David Consiglio, Jr.)

%e 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

%o (Python)

%o from itertools import combinations_with_replacement as cwr

%o from collections import defaultdict

%o keep = defaultdict(lambda: 0)

%o power_terms = [x**4 for x in range(1, 500)]

%o for pos in cwr(power_terms, 3):

%o     tot = sum(pos)

%o     keep[tot] += 1

%o rets = sorted([k for k, v in keep.items() if v >= 6])

%o for x in range(len(rets)):

%o     print(rets[x])

%Y Cf. A344364, A344648, A344729, A344904, A345083.

%K nonn

%O 1,1

%A _David Consiglio, Jr._, May 25 2021