A141235 - OEIS

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).

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

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OFFSET

1,1

LINKS

EXAMPLE

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

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

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

PROG

(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

CROSSREFS

KEYWORD

nonn,more

AUTHOR

Pierre CAMI, Jun 16 2008

EXTENSIONS

a(9)-a(10) from Michel Marcus, Sep 24 2019

STATUS

approved