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A025468 a(n) is the number of partitions of n into 2 distinct positive cubes. 5
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0

COMMENTS

In other words, number of solutions to the equation n = x^3 + y^3 with x > y > 0. The first value > 1 is a(1729) = 2. - Antti Karttunen, Aug 29 2017

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..100000

Index entries for sequences related to sums of cubes

FORMULA

From Antti Karttunen, Aug 28-29 2017: (Start)

a(n) = A025465(n) - A025469(n).

a(n) <= A025455(n).

(End)

PROG

(Scheme) (define (A025468 n) (let loop ((x (A048766 n)) (s 0)) (let* ((x3 (A000578 x)) (y3 (- n x3))) (if (<= x3 y3) s (loop (- x 1) (+ s (if (and (> y3 0) (= (A000578 (A048766 y3)) y3)) 1 0))))))) ;; Antti Karttunen, Aug 28 2017

CROSSREFS

Cf. A000578, A048766, A025455, A025465, A025469.

Sequence in context: A037817 A297039 A239705 * A025465 A323514 A302047

Adjacent sequences:  A025465 A025466 A025467 * A025469 A025470 A025471

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified June 23 13:01 EDT 2021. Contains 345401 sequences. (Running on oeis4.)