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%I #26 Sep 08 2022 08:45:02
%S 9,27,243,2187,177147,1594323,129140163,1162261467,94143178827,
%T 68630377364883,617673396283947,450283905890997363,
%U 36472996377170786403,328256967394537077627,26588814358957503287787
%N a(n) = 3^prime(n).
%H Vincenzo Librandi, <a href="/A057901/b057901.txt">Table of n, a(n) for n = 1..100</a>
%F a(n) = 3^A000040(n).
%F Sum_{n>=1} 1/a(n) = A132800. - _Amiram Eldar_, Aug 11 2020
%e a(4) = 3^7 = 2187.
%t 3^Prime@Range@30 (* _Vladimir Joseph Stephan Orlovsky_, Apr 11 2011 *)
%o (Magma) [3^p: p in PrimesUpTo(30)]; // _Vincenzo Librandi_, Jun 03 2014
%Y Cf. A034785, A053810, A057902, A132800.
%Y Subsequence of A000244 (powers of 3).
%K nonn
%O 1,1
%A _Henry Bottomley_, Sep 29 2000
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