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A085323 Numbers k such that both k and k+1 are sums of two positive cubes. 3
854, 4940, 9603, 10744, 17919, 29743, 62558, 79001, 133273, 164304, 193192, 205406, 214984, 242648, 263871, 378936, 431999, 447336, 488375, 517427, 610687, 731158, 762047, 1000511, 1061550, 1125207, 1134124, 1157632, 1158137, 1179520 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are 664 terms < 8*10^9, a(664)=7999968373. - Zak Seidov, Jul 24 2009

This is an infinite sequence. To see why, consider the (N,N+1) pair N = 16*k^6 - 12*k^4 + 6*k^2 - 2 = (2*k^2 - k - 1)^3 + (2*k^2 + k -1)^3 and N + 1 = 16*k^6 - 12*k^4 + 6*k^2 - 1 = (2*k^2)^3 + (2*k^2 - 1)^3. - Ant King, Sep 20 2013

LINKS

Zak Seidov, Table of n, a(n) for n = 1..664

EXAMPLE

854 = 9^3 + 5^3 and 855 = 8^3 + 7^3;

4940 = 17^3 + 3^3 and 4941 = 13^3 + 14^3.

MATHEMATICA

{m=100, k=3, m^k}; t=Union[Flatten[Table[Table[w^k+q^k, {w, 1, m}], {q, 1, m}]]]; dt=Delete[ -RotateRight[t]+t, 1]; p=Part[t, Flatten[Position[dt, 1]]]; p

CROSSREFS

Cf. A003325.

Sequence in context: A127593 A248856 A251050 * A185639 A105275 A100969

Adjacent sequences:  A085320 A085321 A085322 * A085324 A085325 A085326

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 01 2003

EXTENSIONS

Corrected and extended by Zak Seidov, Jul 24 2009

Name and Example edited by Jon E. Schoenfield, Jul 29 2017

STATUS

approved

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Last modified December 14 02:56 EST 2018. Contains 318087 sequences. (Running on oeis4.)