%I #5 Oct 11 2013 21:21:01
%S 2,3,5,6,7,8,10,12,13,14,16,17,20,21,25,26,28,29,31,33,35,39,41,43,44,
%T 45,49,51,52,57,60,64,67,69,70,81,83,85,89,90,91,97,98,104,109,113,
%U 116,118,120,131,134,136,140,142,144,145,148,152,157,171,173
%N Numbers for which A061214(n) + 1 is prime, where A061214(n) = product of composite numbers between prime(n) and prime(n+1) .
%e a(2) = 2 because 4 + 1 is prime; a(3) = 3 because 6 + 1 is prime; 4 is not in A229992 because 8*9*10 + 1 is not prime.
%t q[n_] := Product[k, {k, Prime[n] + 1, Prime[n + 1] - 1}]; c[n_] := If[PrimeQ[q[n] + 1], 1, 0]; t = Table[c[n], {n, 1, 230}]; u = Rest[Flatten[Position[t, 1]]]
%Y Cf. A061214, A229992.
%K nonn
%O 2,1
%A _Clark Kimberling_, Oct 09 2013
|