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a(n) = 2^prime(n)-prime(n).
3

%I #19 Sep 08 2022 08:45:15

%S 2,5,27,121,2037,8179,131055,524269,8388585,536870883,2147483617,

%T 137438953435,2199023255511,8796093022165,140737488355281,

%U 9007199254740939,576460752303423429,2305843009213693891

%N a(n) = 2^prime(n)-prime(n).

%H N. J. A. Sloane, <a href="/A100105/b100105.txt">Table of n, a(n) for n = 1..100</a>

%p seq( (2^ithprime(x)-ithprime(x)),x=1..20);

%t f[n_]:=(2^Prime[n]-Prime[n]); Array[f,4!,1] (* _Vladimir Joseph Stephan Orlovsky_, Oct 17 2009 *)

%o (Magma) [2^p - p: p in PrimesUpTo(80)]; // _Vincenzo Librandi_, Jun 03 2014

%Y Cf. A001348, A034785.

%K nonn

%O 1,1

%A _Jorge Coveiro_, Dec 26 2004