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A344926
Numbers that are the sum of four fourth powers in nine or more ways.
7
328118259, 385202034, 395613234, 489597858, 592417938, 625839858, 641398338, 674511618, 677125218, 693239634, 699598578, 722302434, 779889314, 780278643, 780595299, 781388643, 782999714, 791204514, 792005379, 797405714, 797935698, 803898018, 805299699
OFFSET
1,1
LINKS
David Consiglio, Jr., Table of n, a(n) for n = 1..79
EXAMPLE
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.
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, 4):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 9])
for x in range(len(rets)):
print(rets[x])
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved