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%I #8 Apr 25 2016 12:05:00
%S 2,3,113,5,13,7,17,19,257,11,9157,13,29,31,401,17,37,19,41,43,
%T 82440101,23,593,617,53,1117601,
%U 71222359652296203545715260298095475932840563720928496792310817334884559392569395657640073370291521
%N Let the sequence s_n be defined by s_n(1) = n+1 and for k > 1, s_n(k) = k*s_n(k-1)+1. Then a(n) is the first prime in the sequence s_n.
%C For n = 10r+1, a(n) >= s_n(6).
%e a(3) = 113: 3+1 = 4 is composite, 2*4+1 = 9 is composite, 3*9+1 = 28 is composite, 4*28+1 = 113 is prime.
%o (MATLAB) s = n + 1; k = 2; while (~isprime(s)) s = k*s + 1; k = k + 1; end a = s
%K nonn,hard
%O 1,1
%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 16 2003
%E Edited and extended by _David Wasserman_, Sep 09 2003
%E One more term from _David Wasserman_, Jan 05 2005