OFFSET
1,2
COMMENTS
If n belongs to this sequence then so does n*m^4 for any positive integer m. Primitive elements (i.e., not of the form n*m^4 for m>1) are listed in A147858.
There is no square in this sequence except 0. - Altug Alkan, Apr 08 2016
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
N:= 10^4: # to get all terms <= N
Res:= {0}:
for a from 1 to floor(sqrt(N-2)) do
if a^4 > N then bmin:= ceil((a^4-N)^(1/4)) else bmin:= 1 fi;
Res:= Res union {seq(a^4-b^4, b=bmin..a-1)}
od:
sort(convert(Res, list)); # Robert Israel, Sep 28 2018
MATHEMATICA
nn = 50; Take[Union @@ Map[Differences, Union@ Map[Sort@ # &, Tuples[Range[Ceiling[nn/3]], {2}]]^4], nn] (* Michael De Vlieger, Apr 09 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Nov 15 2008, Nov 19 2008
EXTENSIONS
Offset changed by Robert Israel, Sep 28 2018
STATUS
approved