OFFSET
1,2
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
3 is a term because 3 = (2^2-1)*(0^2+1).
MAPLE
N:= 10000: # to get all terms <= N
S:= {0, seq(seq((a^2-1)*(b^2+1), b=0 .. floor(sqrt(N/(a^2-1)-1))), a=2..floor(sqrt(N+1)))}:
sort(convert(S, list)); # Robert Israel, May 05 2016
MATHEMATICA
TakeWhile[#, Function[k, k < Sqrt@ Max@ #]] &@ Select[DeleteDuplicates@ Sort[(#1^2 - 1) (#2^2 + 1) & @@@ Tuples[Range[0, 25], 2]], # >= 0 &] (* Michael De Vlieger, May 02 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Apr 01 2010
EXTENSIONS
Name clarified by Altug Alkan, May 02 2016
STATUS
approved