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A344645 Numbers that are the sum of four fifth powers in exactly two ways. 5
51445, 876733, 1646240, 3558289, 4062500, 5687000, 7962869, 8227494, 9792364, 9924675, 10908544, 12501135, 15249850, 18317994, 18804544, 20611151, 20983875, 21297837, 23944908, 24201342, 24598407, 27806867, 28055456, 29480343, 31584102, 32557875, 32814683, 35469555, 40882844, 45177175 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Differs from A344644 at term 508 because 1479604544 = 3^5 + 49^5 + 53^5 + 62^5 = 14^5 + 37^5 + 52^5 + 65^5 = 19^5 + 37^5 + 45^5 + 67^5

LINKS

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

EXAMPLE

1646240 is a term because 1646240 = 9^5 + 15^5 + 15^5 + 15^5 = 11^5 + 13^5 + 13^5 + 17^5

PROG

from itertools import combinations_with_replacement as cwr

from collections import defaultdict

keep = defaultdict(lambda: 0)

power_terms = [x**5 for x in range(1, 500)]

for pos in cwr(power_terms, 4):

    tot = sum(pos)

    keep[tot] += 1

rets = sorted([k for k, v in keep.items() if v == 2])

for x in range(len(rets)):

    print(rets[x])

CROSSREFS

Cf. A342686, A344193, A344642, A344644.

Sequence in context: A203405 A152512 A344644 * A203354 A289823 A147530

Adjacent sequences:  A344642 A344643 A344644 * A344646 A344647 A344648

KEYWORD

nonn

AUTHOR

David Consiglio, Jr., May 25 2021

STATUS

approved

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Last modified October 26 14:28 EDT 2021. Contains 348267 sequences. (Running on oeis4.)