A344922 Numbers that are the sum of four fourth powers in seven or more ways.

6576339, 13155858, 16020018, 16408434, 22673634, 23056803, 26421474, 33734834, 35965458, 39786098, 39803778, 43583138, 51071619, 52652754, 53731458, 57976083, 63985314, 64365939, 67655779, 68846274, 73744563, 75951138, 77495778, 87038883, 88648914, 89148114

Offset

1,1

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..1000

Example

6576339 is a term because 6576339 = 1^4 + 24^4 + 41^4 + 43^4  = 3^4 + 7^4 + 41^4 + 44^4  = 4^4 + 23^4 + 27^4 + 49^4  = 6^4 + 31^4 + 41^4 + 41^4  = 7^4 + 11^4 + 36^4 + 47^4  = 7^4 + 21^4 + 28^4 + 49^4  = 12^4 + 17^4 + 29^4 + 49^4.

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 == 7])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A344729, A344904, A344923, A344924, A344942, A345150.

Sequence in context: A115615 A257016 A234090 * A344923 A204404 A266914

Adjacent sequences: A344919 A344920 A344921 * A344923 A344924 A344925

Keyword

nonn

Author

David Consiglio, Jr., Jun 02 2021

Status

approved