%I A006450 M2477
%S A006450 3,5,11,17,31,41,59,67,83,109,127,157,179,191,211,241,277,283,331,353,
%T A006450 367,401,431,461,509,547,563,587,599,617,709,739,773,797,859,877,919,
%U A006450 967,991,1031,1063,1087,1153,1171,1201,1217,1297,1409,1433,1447,1471
%N A006450 Primes with prime subscripts.
%C A006450 Sometimes called Prime-Index-Primes or PIPs. - Jonathan Vos Post, Jul 
               19 2008
%C A006450 A000040 = A006450 U A007821. - Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), 
               Sep 24 2009
%D A006450 R. E. Dressler and S. T. Parker, Primes with a prime subscript, J. ACM, 
               22 (1975), 380-381.
%D A006450 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A006450 T. D. Noe, <a href="b006450.txt">Table of n, a(n) for n = 1..1000</a>
%H A006450 Paul Cooijmans, <a href="http://web.archive.org/web/20050302171708/http:/
               /members.chello.nl/p.cooijmans/gliaweb/tests/num.html">Numbers</a>
               .
%H A006450 Paul Cooijmans, <a href="http://web.archive.org/web/20031006141136/http:/
               /members.chello.nl/p.cooijmans/gliaweb/tests/tfg/tfgshort.html">Short 
               Test For Genius</a>.
%H A006450 N. Fernandez, <a href="http://www.borve.org/primeness/FOP.html">An order 
               of primeness, F(p)</a>
%H A006450 N. Fernandez, <a href="http://www.borve.org/primeness/moreterms.html">
               More terms of this and other sequences related to A049076.</a>
%F A006450 a(n)=prime(prime(n))=A000040(A000040(n)). - Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), 
               Sep 24 2009
%e A006450 a(5)=31 because a(5)=p(p(5))=p(11)=31
%p A006450 seq(ithprime(ithprime(i)),i=1..50); - Uli Baum (Uli_Baum(AT)gmx.de), 
               Sep 05 2007
%t A006450 Table[ Prime[ Prime[ n ] ], {n, 1, 51} ]
%Y A006450 Primes for which A049076 > 1.
%Y A006450 Cf. A049076, A007821, A000040, A038580, A049090, A049203, A049202, A057849, 
               A057850, A057851, A057847, A058332, A093047.
%Y A006450 Sequence in context: A090795 A087732 A108542 this_sequence A085918 A146622 
               A124179
%Y A006450 Adjacent sequences: A006447 A006448 A006449 this_sequence A006451 A006452 
               A006453
%K A006450 nonn,easy,nice
%O A006450 1,1
%A A006450 Jeffrey Shallit, sm