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A344187
Numbers that are the sum of two positive fourth powers in exactly one way.
6
2, 17, 32, 82, 97, 162, 257, 272, 337, 512, 626, 641, 706, 881, 1250, 1297, 1312, 1377, 1552, 1921, 2402, 2417, 2482, 2592, 2657, 3026, 3697, 4097, 4112, 4177, 4352, 4721, 4802, 5392, 6497, 6562, 6577, 6642, 6817, 7186, 7857, 8192, 8962, 10001, 10016, 10081, 10256, 10625, 10657, 11296, 12401, 13122, 14096, 14642
OFFSET
1,1
COMMENTS
Differs from A003336 at term 11660 because 635318657 = 59^4 + 158^4 = 133^4 + 134^4
LINKS
David Consiglio, Jr., Table of n, a(n) for n = 1..20000
EXAMPLE
32 is a member of this sequence because 32 = 2^4 + 2^4
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, 50)]
for pos in cwr(power_terms, 2):
tot = sum(pos)
keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v == 1])
for x in range(len(rets)):
print(rets[x])
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved