The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A175362 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A175362

Number of integer pairs (x,y) satisfying |x|^3 + |y|^3 = n, -n <= x,y <= n.
(history; published version)

#29 by Sean A. Irvine at Thu Aug 26 19:15:54 EDT 2021

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proposed

approved

#28 by Daniel Suteu at Mon Aug 16 03:32:39 EDT 2021

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editing

proposed

#27 by Daniel Suteu at Mon Aug 16 03:32:03 EDT 2021

PROG

(PARI) a(n) = if(n==0, 1, 4*sum(k=1, sqrtnint(n, 3), ispower(n - k^3, 3))); \\ Daniel Suteu, Aug 16 2021

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proposed

editing

#26 by Daniel Suteu at Sun Aug 15 16:03:15 EDT 2021

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editing

proposed

#25 by Daniel Suteu at Sun Aug 15 16:02:49 EDT 2021

FORMULA

a(n) = 4*Sum_{k=1..floor(n^(1/3))} A010057(n - k^3), for n > 0. - Daniel Suteu, Aug 15 2021

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approved

editing

#24 by Bruno Berselli at Fri Jan 27 05:21:46 EST 2017

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reviewed

approved

#23 by Joerg Arndt at Fri Jan 27 04:23:14 EST 2017

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proposed

reviewed

#22 by Jon E. Schoenfield at Thu Jan 26 19:25:03 EST 2017

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editing

proposed

#21 by Jon E. Schoenfield at Thu Jan 26 19:25:01 EST 2017

NAME

Number of integer pairs (x,y) satisfying |x|^3 + |y|^3 = n, -n <= x,y <= n.

COMMENTS

a(n) >= 16 for n in A001235.

FORMULA

G.f.: ( 1 + 2 * sum_(Sum_{j>=1) } x^(j^3) )^2.

CROSSREFS

Cf. A001235, A010057, A011541, A121980, A025468, A025464, A025446, A025455, A010057A025464, A025468, A121980.

EXTENSIONS

Removed invalid Invalid claim that belonged to A004018 - _removed by _R. J. Mathar_, Apr 24 2010

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proposed

editing

#20 by Robert Israel at Thu Jan 26 17:53:02 EST 2017

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editing

proposed