login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A141235 Sequence of k such that starting with P(0)=13 then k(n)*P(n-1)*(k(n)*P(n-1)-1)-1 is the least prime = P(n). 2

%I

%S 3,2,15,8,11,70,271,429,189,109

%N Sequence of k such that starting with P(0)=13 then k(n)*P(n-1)*(k(n)*P(n-1)-1)-1 is the least prime = P(n).

%e 1*13*(1*13-1)-1=155 composite,

%e 2*13*(2*13-1)-1=649 composite,

%e 3*13*(3*13-1)-1=1481 prime so a(1)=3 and P(1)=1481.

%o (PARI) P=13; for(i=1, 20, k=0; while(!ispseudoprime(t=k++*P*(k*P-1)-1), ); P=t; print1(k", ")) \\ _Michel Marcus_, Sep 24 2019

%Y Cf. A141233, A141234, A141236, A141237, A141238, A141239, A141240.

%K nonn,more

%O 1,1

%A _Pierre CAMI_, Jun 16 2008

%E a(9)-a(10) from _Michel Marcus_, Sep 24 2019

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 14 10:04 EST 2019. Contains 329111 sequences. (Running on oeis4.)