%I #22 Oct 01 2024 15:45:24
%S 1,2,10,20,30,34,36,50,60,100,108,110,112,114,122,130,156,188,192,198,
%T 204,208,210,216,230,234,240,246,250,260,286,290,294,300,330,332,338,
%U 342,360,388,390,392,410,416,440,460,468,484,492,502,532,542,556,570
%N Numbers k such that k^2 + prime(k)^2 is a prime.
%H Amiram Eldar, <a href="/A177150/b177150.txt">Table of n, a(n) for n = 1..10000</a>
%e 100 is in the sequence because the 100th prime is 541, and 100^2 + 541^2 = 302681 is prime.
%p with(numtheory): nn:= 150: T:=array(1..nn):k:=1:for n from 1 to 1764 do:p:=ithprime(n):if type(p^2+n^2,prime)=true then T[k]:=n:k:=k+1: else fi:od:print(T):
%t Select[Range[600], PrimeQ[#^2 + Prime[#]^2] &] (* _Amiram Eldar_, Aug 11 2019 *)
%o (Magma) [m:m in [1..600] | IsPrime(m^2+NthPrime(m)^2)]; // _Marius A. Burtea_, Aug 11 2019
%Y Cf. A106587.
%K nonn
%O 1,2
%A _Michel Lagneau_, May 03 2010