A344240 Numbers that are the sum of three fourth powers in exactly three ways.

811538, 1733522, 2798978, 3750578, 4614722, 6573938, 7303842, 8878898, 12771458, 12984608, 13760258, 14677362, 15601698, 16196193, 17868242, 21556178, 22349522, 25190802, 25589858, 27736352, 29969282, 41532498, 44048498, 44783648, 45182018, 50944418, 54894242, 57052562, 59165442, 60009248

Offset

1,1

Comments

Differs from A344239 at term 6 because 5978882 = 3^4 + 40^4 + 43^4 = 8^4 + 37^4 + 45^4 = 15^4 + 32^4 + 47^4 = 23^4 + 25^4 + 48^4

Links

David Consiglio, Jr., Table of n, a(n) for n = 1..5129

Example

2798978 is a member of this sequence because 2798978 = 6^4 + 31^4 + 37^4 = 9^4 + 29^4 + 38^4 = 13^4 + 26^4 + 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, 50)]
for pos in cwr(power_terms, 3):
    tot = sum(pos)
    keep[tot] += 1
rets = sorted([k for k, v in keep.items() if v == 3])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A025397, A344192, A344239, A344242, A344278.

Sequence in context: A083617 A343082 A344239 * A238522 A210060 A237790

Adjacent sequences: A344237 A344238 A344239 * A344241 A344242 A344243

Keyword

nonn

Author

David Consiglio, Jr., May 12 2021

Status

approved