%I A106790
%S A106790 1,1,3,1,2,1,7,2,2,1,4,1,2,5,15,1,2,1,4,2,2,1,23,2,6,4,4,1,7,1,31,10,6,
%T A106790 10,4,1,18,15,9,1,2,1,17,2,2,1,23,2,4,20,6,1,6,8,10,6,2,1,59,1,2,25,63,
%U A106790 2,2,1,67,8,2,1
%N A106790 Smallest k>0 such that binomial(n,k) + 1 is prime.
%C A106790 a(n) <= n; for primes p: a(p-1) = 1.
%C A106790 The values of n for which a(n)=n yield the sequence A067317. - Emeric 
               Deutsch (deutsch(AT)duke.poly.edu), Aug 27 2007
%p A106790 a:=proc(n) local k: for k while isprime(1+binomial(n,k))=false do end 
               do: k end proc: seq(a(n), n=1..70); - Emeric Deutsch (deutsch(AT)duke.poly.edu), 
               Aug 27 2007
%Y A106790 Cf. A000040, A067317.
%Y A106790 Sequence in context: A039620 A008296 A140185 this_sequence A078897 A011086 
               A103514
%Y A106790 Adjacent sequences: A106787 A106788 A106789 this_sequence A106791 A106792 
               A106793
%K A106790 nonn
%O A106790 1,3
%A A106790 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 16 2005
%E A106790 Corrected and extended by Emeric Deutsch (deutsch(AT)duke.poly.edu), 
               Aug 27 2007