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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
3, 2, 15, 8, 11, 70, 271, 429, 189, 109 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

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

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

Sequence in context: A142705 A072346 A103236 * A199167 A218969 A185973

Adjacent sequences:  A141232 A141233 A141234 * A141236 A141237 A141238

KEYWORD

nonn,more

AUTHOR

Pierre CAMI, Jun 16 2008

EXTENSIONS

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

STATUS

approved

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Last modified October 21 11:42 EDT 2019. Contains 328296 sequences. (Running on oeis4.)