OFFSET
1,1
COMMENTS
This sequence is infinite, since if n is in the sequence so is n*k^3 for all k > 0; thus a(n) << n^3. - Charles R Greathouse IV, Nov 29 2014
LINKS
Rosalie Fay, Table of n, a(n) for n = 1..100
Joseph H. Silverman, Taxicabs and sums of two cubes, Amer. Math. Monthly, 100 (1993), 331-340.
EXAMPLE
42549416 = 348^3+74^3 = 282^3+272^3 = (-2662)^3+2664^3 = (-475)^3+531^3, so 42549416 is in the sequence. (Silverman)
PROG
(PARI) T=thueinit('z^3+1); is(n)=my(v=thue(T, n)); #v>6 && #select(u->u[1]<=u[2], v)>3 \\ Charles R Greathouse IV, Nov 29 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(6)-a(22) from Donovan Johnson, Apr 17 2010
Missing terms 42549416, 48275136, 94287375, 111209679, 124454421 added by Rosalie Fay, Oct 13 2017
STATUS
approved