A258081 - OEIS

%I #15 Jun 05 2015 06:33:05

%S 1,1,1,1,2,10,12,10,21,25,70,670,239,2115,586,1619,26800,2505,99019,

%T 40903,285641,67166,1852765

%N Values of k in A071580.

%C The first 23 terms were found using gwnum, and the first 22 have been independently checked using gmp.

%H Mersenne Forum, <a href="http://mersenneforum.org/showthread.php?t=20260">A071580</a>

%o (PARI) terms=12; p=2; for(n=2, terms, q=p+1; while(!ispseudoprime(q), q=q+p); print1(q\p,", "); p=p*q) \\ _Serge Batalov_, May 19 2015

%Y Cf. A061092, A072532, A113334.

%K nonn,hard,more

%O 1,5

%A _Andrew R. Booker_, May 19 2015