OFFSET
1,1
COMMENTS
List of distinct members of A263979.
The sequence is infinite; see Sierpinski (1988), p. 221.
REFERENCES
W. Sierpinski, Elementary Theory of Numbers, 2nd English edition, revised and enlarged by A. Schinzel, Elsevier, 1988.
FORMULA
a(n) == 1 or 2 mod 4.
EXAMPLE
The smallest prime of the form a^2 + b^2 with a > 2 and b > 2 is 41 = 4^2 + 5^2, so 41 is a member.
5 = 1^2 + 2^2 is a prime of the form a^2 + b^2 with a > 0 and b > 0, but 5 is not a member, because 2 = 1^2 + 1^2 is a smaller prime of that form.
MATHEMATICA
Union[Table[
Min[Select[
Union[
Flatten[
With[{n = k},
Array[#1^2 + #2^2 &, { 2 n + 1, 2 n + 1}, {n + 1, n + 1}]]]],
PrimeQ]], {k, 0, 99}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Sondow, Nov 09 2015
STATUS
approved