A344356 Numbers that are the sum of four fourth powers in five or more ways.

2147874, 2266338, 2690658, 3189603, 3464178, 3754674, 3847554, 4030419, 4165794, 4457298, 4884114, 5229378, 5624739, 5978883, 5980178, 5981283, 6014178, 6044418, 6134994, 6258723, 6313953, 6400194, 6576339, 6593538, 6612354, 6899603, 7088898, 7498323, 7811874, 7918498, 8064018, 8292323

Offset

1,1

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..20000

Example

2690658 is a term of this sequence because 2690658 = 2^4 + 8^4 + 33^4 + 35^4 = 3^4 + 4^4 + 19^4 + 40^4 = 7^4 + 8^4 + 30^4 + 37^4 = 9^4 + 21^4 + 30^4 + 36^4 = 16^4 + 25^4 + 32^4 + 33^4.

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, 4):
    tot = sum(pos)
    keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v >= 5])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A343987, A344352, A344357, A344358, A344364, A344904.

Sequence in context: A235930 A178227 A154709 * A344357 A184476 A144587

Adjacent sequences: A344353 A344354 A344355 * A344357 A344358 A344359

Keyword

nonn

Author

David Consiglio, Jr., May 15 2021

Status

approved