A157036 Shorthand for A157035, the largest prime with 2^n digits.

3, 3, 27, 11, 63, 21, 51, 17, 813, 377, 7017, 27381, 7763, 1133, 119387, 67347, 121877

Offset

0,1

Comments

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

Links

Table of n, a(n) for n=0..16.

Formula

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

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

Maple

a:= n-> (t-> t-prevprime(t))(10^(2^n)):
seq(a(n), n=0..10);  # Alois P. Heinz, Mar 02 2022

Prog

(PARI) { a(n) = 10^(2^n) - precprime(10^(2^n)) } \\ Max Alekseyev, Mar 28 2009
(Python)
from sympy import prevprime
def a(n): return 10**(2**n) - prevprime(10**(2**n))
print([a(n) for n in range(10)]) # Michael S. Branicky, Mar 02 2022

Crossrefs

Cf. A033874, A157034, A157035.

Sequence in context: A363471 A303822 A326176 * A080302 A080272 A369013

Adjacent sequences: A157033 A157034 A157035 * A157037 A157038 A157039

Keyword

nonn,base,more

Author

Lekraj Beedassy, Feb 22 2009

Extensions

a(8)-a(13) from Ray Chandler and Max Alekseyev, Mar 22 2009

a(14) from Jinyuan Wang, Feb 22 2022

a(15) from Michael S. Branicky, Jun 19 2024

a(16) from Michael S. Branicky, Jun 27 2024

Status

approved