OFFSET
1,1
COMMENTS
Main sequence is A003828.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..4999
EXAMPLE
a(1) = 422481 because 422481^4 = 95800^4 + 217519^4 + 414560^4.
a(61) = 20615673 because 20615673^4 = 2682440^4 + 15365639^4 + 18796760^4.
MATHEMATICA
Select[Range[100], (p = PowersRepresentations[#^4, 3, 4]; (Select[p, #[[1]] > 0 && #[[2]] > 0 && #[[3]] > 0 &] != {})) &] (* Jinyuan Wang, Feb 20 2020 *)
PROG
(PARI) is(n) = for(a=sqrtnint(n^4\3, 4), n-1, for(b=1, a, for(c=1, b, if(n^4==a^4+b^4+c^4, return(1))))); 0; \\ Charles R Greathouse IV, Aug 29 2013 and slightly modified by Jinyuan Wang, Feb 20 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jul 24 2010
EXTENSIONS
Terms and example corrected by Charles R Greathouse IV, Aug 29 2013
First 0 removed by Jinyuan Wang, Feb 20 2020
STATUS
approved