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A344237 Numbers that are the sum of five fourth powers in exactly two ways. 8
260, 275, 340, 515, 884, 1555, 2595, 2660, 2675, 2690, 2705, 2755, 2770, 2835, 2930, 2945, 3010, 3185, 3299, 3314, 3379, 3554, 3923, 3970, 3985, 4050, 4115, 4145, 4160, 4210, 4290, 4355, 4400, 4465, 4594, 4769, 4834, 5075, 5090, 5155, 5265, 5330, 5395, 5440, 5505, 5570, 5699, 6370, 6545, 6580, 6595, 6660, 6675 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Differs from A344237 at term 31 because 4225 = 2^4 + 2^4 + 2^4 + 3^4 + 8^4 = 2^4 + 4^4 + 4^4 + 6^4 + 7^4 = 3^4 + 4^4 + 6^4 + 6^4 + 6^4

LINKS

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

EXAMPLE

340 is a member of this sequence because 340 = 1^4 + 1^4 + 1^4 + 3^4 + 4^4 = 2^4 + 3^4 + 3^4 + 3^4 + 3^4

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, 5):

    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. A048927, A342686, A344190, A344193, A344238, A344244, A345814.

Sequence in context: A252248 A214471 A344238 * A139408 A253504 A154379

Adjacent sequences:  A344234 A344235 A344236 * A344238 A344239 A344240

KEYWORD

nonn

AUTHOR

David Consiglio, Jr., May 12 2021

STATUS

approved

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Last modified September 26 20:34 EDT 2021. Contains 347672 sequences. (Running on oeis4.)