[seqfan] Re: 2^n + p = prime/composite
Ray Chandler
rayjchandler at sbcglobal.net
Wed Feb 24 17:32:23 CET 2010
I do not find either of them in the OEIS, but a(n)+b(n)= A007053(n).
Ray
>
> Are either of these sequences already in the EIS, possibly
> with a different (non-obviously identical) definition?
>
> a) a(n) = number of primes p, p <= 2^n, where 2^n + p is prime.
> (Offset = 0).
> 0,0,1,2,3,3,5,...
>
> b) b(n) = number of primes p, p <= 2^n, where 2^n + p is composite.
> (Offset = 0).
>
> 0,1,1,2,3,8,13,...
>
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