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A224483 Numbers which are the sum of two positive cubes and divisible by 29. 6
6119, 6293, 6641, 7163, 7859, 8729, 9773, 10991, 12383, 13949, 15689, 17603, 19691, 21953, 48778, 48952, 49474, 50344, 51562, 53128, 55042, 57304, 59914, 62872, 66178, 69832, 73834, 78184, 82882, 87928, 93322, 99064, 105154 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If 12*h-2523 is a square then some values of 29*h are in this sequence.

It is easy to verify that h is of the form 3*m^2-9*m+217, and therefore 29*(3*m^2-9*m+217) = (16-m)^3+(m+13)^3. [Bruno Berselli, May 10 2013]

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

upto[n_] := Block[{t}, Union@Reap[ Do[If[Mod[t = x^3 + y^3, 29] == 0, Sow@t], {x, n^(1/3)}, {y, Min[x, (n - x^3)^(1/3)]}]][[2, 1]]]; upto[106000] (* Giovanni Resta, Jun 12 2020 *)

PROG

(MAGMA) [n: n in [2..2*10^5] | exists{i: i in [1..Iroot(n-1, 3)] | IsPower(n-i^3, 3) and IsZero(n mod 29)}]; // Bruno Berselli, May 10 2013

CROSSREFS

Cf. numbers which are the sum of two positive cubes and divisible by k: A101421 (k=7), A101852 (k=11), A094447 (k=13), A099178 (k=17), A102619 (k=19), A101806 (k=23), A102658 (k=31), A102618 (k=37).

Sequence in context: A235764 A235547 A251368 * A065695 A204368 A114131

Adjacent sequences:  A224480 A224481 A224482 * A224484 A224485 A224486

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, May 08 2013

STATUS

approved

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Last modified March 8 01:41 EST 2021. Contains 341934 sequences. (Running on oeis4.)