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A203018 The n-th prime number that equals 1 (mod 4n).

%I A203018 #8 Oct 30 2018 10:31:02
%S A203018 5,41,61,193,241,337,449,673,613,1201,1453,1249,2081,2633,1861,3457,
%T A203018 4217,3169,6841,4801,4201,7481,9109,6529,7901,13001,8209,12097,12413,
%U A203018 8641,16741,17921,10429,19993,15401,16417,24421,26297,17317,23201,33457,21169
%N A203018 The n-th prime number that equals 1 (mod 4n).
%H A203018 Zak Seidov, <a href="/A203018/b203018.txt">Table of n, a(n) for n = 1..1000</a>
%e A203018 a(1)=5 because 1+4=5 is 1st prime == 1 mod 4,
%e A203018 a(2)=41 because 1+(4*2)*{2,5}={17,41} are 1st and 2nd primes == 1 mod 8,
%e A203018 a(3)=61 because 1+(4*3)*{1,3,5}={13,37,61} are 1st, 2nd and 3rd primes == 1 mod 12;
%e A203018 a(1000)=24952001=1+4000*6238;
%e A203018 a(10000)=3345120001=1+40000*83628;
%e A203018 a(10^5)=411686400001=A000040(16018223727)=1+4*10^6*1029216;
%e A203018 a(10^6)=48792928000001=A000040(1600641618847)=1+4*10^6*12198232.
%Y A203018 Cf. A000040, A002144, A070848.
%K A203018 nonn
%O A203018 1,1
%A A203018 _Zak Seidov_, Dec 27 2011