login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A135053 Greatest integer M(i)=n such that A085427(n)=A085427(n-1)/2 and k(i+1)>k(i) with A085427(n)=least k such that k*2^n-1 is prime ( Mersenne prime when k=1). 1

%I #3 Mar 31 2012 13:22:05

%S 2,21,23,80,96,111,168,230,281,347,558,704

%N Greatest integer M(i)=n such that A085427(n)=A085427(n-1)/2 and k(i+1)>k(i) with A085427(n)=least k such that k*2^n-1 is prime ( Mersenne prime when k=1).

%e A085427 =3,2,1,1,2,1,2,1,5,7,5,3,2,1,5,4,2,1,2,1,14,7,26,13,39,22

%e A(2)=1,A(1)=2 so A(2)=A(1)/2 so M(1)=1

%e A(5)=1,A(4)=2 but A(5)=A(2) ..........

%e A(21)=7,A(20)=14 A(21)=A(20)/2 and A(21)>A(2) so M(2)=21

%Y Cf. A087425, A135054.

%K nonn,uned

%O 1,1

%A _Pierre CAMI_, Nov 15 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 03:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)