A095215 - OEIS

%I #12 May 30 2020 05:08:18

%S 2,2,11,67,3301,670001,670001,2816573,1962598272385996001,

%T 13135299156148920427,8195631610270280813458231,

%U 252695623634706646276208461875953169850197045066143207,381219345970368698157410442059827141986617742456355454248317851,381219345970368698157410442059827141986617742456355454248317851

%N Beginning with 2, greatest prime divisor of the concatenation of all previous terms.

%e Greatest prime divisor of 22 is 11, 2211 is 67.

%o (PARI) lista(nn) = {my(k=2, m); print1(k); for(n=2, nn, print1(", ", k=vecmax(factor(m=eval(Str(m, k)))[, 1]))); } \\ _Jinyuan Wang_, May 24 2020

%K nonn,base

%O 1,1

%A _Amarnath Murthy_, Jun 10 2004

%E More terms from _Robert Gerbicz_, Jun 09 2007

%E Offset corrected and a(12)-a(13) from _Donovan Johnson_, Feb 19 2011

%E a(14) from _Jinyuan Wang_, May 30 2020