OFFSET
1,1
COMMENTS
LINKS
Jean-Christophe Hervé, Table of n, a(n) for n = 1..5000
MATHEMATICA
rs[n_] := Reduce[n == x^2 + y^2, {x, y}, Integers]; rd[n_] := Reduce[0 <= y <= x && n == x^2 - y^2, {x, y}, Integers]; Reap[Do[If[rs[n] == False && rd[n] =!= False, Sow[n]], {n, 0, 140}]][[2, 1]] (* Jean-François Alcover, Oct 26 2015 *)
PROG
(Python)
from itertools import count, islice
from sympy import factorint
def A263737_gen(): # generator of terms
return filter(lambda n:n & 3 != 2 and any(p & 3 == 3 and e & 1 for p, e in factorint(n).items()), count(0))
CROSSREFS
KEYWORD
nonn
AUTHOR
Jean-Christophe Hervé, Oct 25 2015
STATUS
approved