A099049 Numbers n such that n-1 and n+1 are both prime or both composite.

4, 5, 6, 7, 9, 11, 12, 13, 15, 17, 18, 19, 21, 23, 25, 26, 27, 29, 30, 31, 33, 34, 35, 37, 39, 41, 42, 43, 45, 47, 49, 50, 51, 53, 55, 56, 57, 59, 60, 61, 63, 64, 65, 67, 69, 71, 72, 73, 75, 76, 77, 79, 81, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 97, 99, 101, 102, 103, 105, 107