A344926 - OEIS

%I #6 Jul 31 2021 18:22:23

%S 328118259,385202034,395613234,489597858,592417938,625839858,

%T 641398338,674511618,677125218,693239634,699598578,722302434,

%U 779889314,780278643,780595299,781388643,782999714,791204514,792005379,797405714,797935698,803898018,805299699

%N Numbers that are the sum of four fourth powers in nine or more ways.

%H David Consiglio, Jr., <a href="/A344926/b344926.txt">Table of n, a(n) for n = 1..79</a>

%e 328118259 is a term because 328118259 = 2^4 + 77^4 + 109^4 + 111^4  = 8^4 + 79^4 + 93^4 + 121^4  = 18^4 + 79^4 + 97^4 + 119^4  = 21^4 + 77^4 + 98^4 + 119^4  = 27^4 + 77^4 + 94^4 + 121^4  = 34^4 + 77^4 + 89^4 + 123^4  = 46^4 + 57^4 + 103^4 + 119^4  = 49^4 + 77^4 + 77^4 + 126^4  = 61^4 + 66^4 + 77^4 + 127^4.

%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, 1000)]

%o for pos in cwr(power_terms, 4):

%o     tot = sum(pos)

%o     keep[tot] += 1

%o rets = sorted([k for k, v in keep.items() if v >= 9])

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

%o     print(rets[x])

%Y Cf. A341891, A344750, A344924, A344927, A344928, A345146.

%K nonn

%O 1,1

%A _David Consiglio, Jr._, Jun 02 2021