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A345564 Numbers that are the sum of six fourth powers in seven or more ways. 8
21251, 43875, 48276, 49796, 53315, 58035, 58500, 59780, 59795, 59811, 67875, 68306, 69155, 69779, 71955, 72051, 72131, 73970, 74420, 74851, 77010, 80291, 80515, 81875, 82275, 84515, 86436, 86451, 86531, 87075, 87746, 88355, 88595, 88660, 88675, 90355, 91475 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Sean A. Irvine, Table of n, a(n) for n = 1..10000

EXAMPLE

43875 is a term because 43875 = 1^4 + 2^4 + 9^4 + 9^4 + 10^4 + 12^4 = 2^4 + 2^4 + 2^4 + 5^4 + 11^4 + 13^4 = 2^4 + 2^4 + 5^4 + 7^4 + 7^4 + 14^4 = 2^4 + 5^4 + 6^4 + 9^4 + 11^4 + 12^4 = 3^4 + 7^4 + 8^4 + 9^4 + 10^4 + 12^4 = 4^4 + 4^4 + 7^4 + 7^4 + 10^4 + 13^4 = 5^4 + 7^4 + 8^4 + 8^4 + 8^4 + 13^4.

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, 6):

    tot = sum(pos)

    keep[tot] += 1

    rets = sorted([k for k, v in keep.items() if v >= 7])

    for x in range(len(rets)):

        print(rets[x])

CROSSREFS

Cf. A344942, A345516, A345563, A345565, A345573, A345721, A345819.

Sequence in context: A289674 A217265 A345563 * A345819 A345830 A236644

Adjacent sequences:  A345561 A345562 A345563 * A345565 A345566 A345567

KEYWORD

nonn

AUTHOR

David Consiglio, Jr., Jun 20 2021

STATUS

approved

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Last modified August 12 06:43 EDT 2022. Contains 356067 sequences. (Running on oeis4.)