%I #34 Jun 27 2024 09:04:07

%S 3,3,27,11,63,21,51,17,813,377,7017,27381,7763,1133,119387,67347,

%T 121877

%N Shorthand for A157035, the largest prime with 2^n digits.

%C The actual prime A157035(n) is obtained as 10^(2^n) - a(n).

%F a(n) = 10^(2^n) - A157035(n).

%F a(n) = A033874(2^n).

%p a:= n-> (t-> t-prevprime(t))(10^(2^n)):

%p seq(a(n), n=0..10); # _Alois P. Heinz_, Mar 02 2022

%o (PARI) { a(n) = 10^(2^n) - precprime(10^(2^n)) } \\ _Max Alekseyev_, Mar 28 2009

%o (Python)

%o from sympy import prevprime

%o def a(n): return 10**(2**n) - prevprime(10**(2**n))

%o print([a(n) for n in range(10)]) # _Michael S. Branicky_, Mar 02 2022

%Y Cf. A033874, A157034, A157035.

%K nonn,base,more

%O 0,1

%A _Lekraj Beedassy_, Feb 22 2009

%E a(8)-a(13) from _Ray Chandler_ and _Max Alekseyev_, Mar 22 2009

%E a(14) from _Jinyuan Wang_, Feb 22 2022

%E a(15) from _Michael S. Branicky_, Jun 19 2024

%E a(16) from _Michael S. Branicky_, Jun 27 2024