OFFSET
1,1
COMMENTS
Numbers n such that n^k is the sum of two positive cubes for all k not divisible by 3.
The restriction on the values of k is the result of Fermat's Last Theorem.
Inspiration was Taxi-cab number 39312. It is the least number with the property that sequence focuses on.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..1646
EXAMPLE
251370 is a term because 251370 = 29^3 + 61^3 and 251370^2 = 2961^3 + 3339^3.
PROG
(PARI) isA003325(n) = for(k=1, sqrtnint(n\2, 3), ispower(n-k^3, 3) && return(1));
lista(nn) = for(n=1, nn, if(isA003325(n) && isA003325(n^2), print1(n, ", ")));
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jun 10 2016
STATUS
approved