A061063 - OEIS

%I #22 Sep 08 2022 08:45:03

%S 1,23,1199,1672799,2821066795199,7958661108093376400572799,

%T 63340286662973277702728603126500927381164903187199

%N a(n) = 2^(2^n)*3^(2^n) - 2^(2^n) - 3^(2^n).

%C For n = 1, 4, 5, 7, values are primes.

%H Harry J. Smith, <a href="/A061063/b061063.txt">Table of n, a(n) for n = 0..10</a>

%H S. M. Ruiz, <a href="http://www.gallup.unm.edu/~smarandache/NewPrimeNumbers-SMRuiz.html">New Prime Numbers</a>

%F a(n) = 2^(2^n)*3^(2^n)  -2^(2^n) - 3^(2^n).

%t f[n_]:=Module[{n1=2^2^n,n2=3^2^n},n1 n2-n1-n2]; f/@Range[0,7]  (* _Harvey P. Dale_, Apr 04 2011 *)

%o (PARI) { for (n=0, 10, p=2^n; w=2^p; h=3^p; write("b061063.txt", n, " ", w*h - w - h) ) } \\ _Harry J. Smith_, Jul 17 2009

%o (Magma) [6^(2^n) - 2^(2^n) - 3^(2^n): n in [0..12]]; // _Vincenzo Librandi_, Apr 05 2011

%K nonn

%O 0,2

%A _Jason Earls_, May 27 2001