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A369629
Number of solutions to +- 1^4 +- 2^4 +- 3^4 +- ... +- n^4 = 0 or 1.
3
1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 5, 0, 16, 18, 0, 21, 32, 100, 126, 0, 424, 510, 0, 1428, 2792, 5988, 9786, 7, 29058, 45106, 22, 150437, 276828, 473854, 836737, 1838, 2455340, 4777436, 15847, 14696425, 27466324, 46429640, 83010230, 738627
OFFSET
0,17
LINKS
PROG
(Python)
from itertools import count, islice
from collections import Counter
def A369629_gen(): # generator of terms
ccount = Counter({0:1})
yield 1
for i in count(1):
bcount = Counter()
for a in ccount:
bcount[a+(j:=i**4)] += ccount[a]
bcount[a-j] += ccount[a]
ccount = bcount
yield(ccount[0]+ccount[1])
A369629_list = list(islice(A369629_gen(), 20)) # Chai Wah Wu, Jan 29 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 28 2024
EXTENSIONS
a(46)-a(50) from Chai Wah Wu, Jan 29 2024
STATUS
approved