A344904 Numbers that are the sum of four fourth powers in six or more ways.

3847554, 5624739, 6044418, 6576339, 6593538, 6899603, 9851058, 10456338, 11645394, 12378018, 13155858, 13638738, 16020018, 16408434, 16990803, 19081089, 20622338, 20649603, 20755218, 20795763, 22673634, 23056803, 24174003, 24368769, 25265553, 25850178

Offset

1,1

Links

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

Example

3847554 is a term because 3847554 = 2^4 + 13^4 + 29^4 + 42^4  = 2^4 + 21^4 + 22^4 + 43^4  = 6^4 + 11^4 + 17^4 + 44^4  = 6^4 + 31^4 + 32^4 + 37^4  = 9^4 + 29^4 + 32^4 + 38^4  = 13^4 + 26^4 + 32^4 + 39^4.

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 >= 6])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A344356, A344647, A344921, A344922, A344940, A345148.

Sequence in context: A253542 A210266 A036474 * A344921 A204812 A205421

Adjacent sequences: A344901 A344902 A344903 * A344905 A344906 A344907

Keyword

nonn

Author

David Consiglio, Jr., Jun 02 2021

Status

approved