A229992 Numbers for which A061214(n) + 1 is prime, where A061214(n) = product of composite numbers between prime(n) and prime(n+1) .

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, 45, 49, 51, 52, 57, 60, 64, 67, 69, 70, 81, 83, 85, 89, 90, 91, 97, 98, 104, 109, 113, 116, 118, 120, 131, 134, 136, 140, 142, 144, 145, 148, 152, 157, 171, 173

Offset: 2

Author

Clark Kimberling, Oct 09 2013

Keywords

• nonn

Examples

			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.
		

Crossrefs

Cf. A061214, A229992.

Programs

Mathematica

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]]]