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A177150 Numbers n such that n^2 + prime(n)^2 is a prime. 1

%I

%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 n such that n^2 + prime(n)^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

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Last modified February 27 01:52 EST 2020. Contains 332299 sequences. (Running on oeis4.)