A343967 Numbers that are the sum of three positive cubes in five or more ways.

161568, 262683, 314712, 326808, 359568, 443197, 444536, 471960, 503208, 513729, 515376, 526023, 529199, 532683, 552824, 597960, 702729, 736371, 746992, 806688, 844416, 863379, 907479, 924048, 931419, 975213, 1011067, 1028663, 1062937, 1092853, 1152152, 1172016, 1211048, 1232496, 1258011

Offset

1,1

Links

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

Example

314712 =  4^3 +  6^3 + 68^3
       =  5^3 + 24^3 + 67^3
       =  6^3 + 30^3 + 66^3
       = 31^3 + 41^3 + 60^3
       = 36^3 + 48^3 + 54^3
so 314712 is a term of this sequence.

Prog

(Python)
from itertools import combinations_with_replacement as cwr
from collections import defaultdict
keep = defaultdict(lambda: 0)
power_terms = [x**3 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 >= 5])
for x in range(len(rets)):
    print(rets[x])

Crossrefs

Cf. A025333, A051167, A343968, A343970, A343987, A344364, A345083.

Sequence in context: A233891 A339498 A249880 * A343970 A349774 A184474

Adjacent sequences: A343964 A343965 A343966 * A343968 A343969 A343970

Keyword

nonn

Author

David Consiglio, Jr., May 05 2021

Status

approved