A083192 - OEIS

A083192

a(1) = 1, then the rearrangement of composite numbers such that the concatenation of n terms from the n-th term is a prime. (Concatenation of n-th term to (2n-1)th term is a prime number).

1, 4, 21, 6, 49, 8, 77, 9, 39, 10, 81, 12, 221, 14, 63, 15, 203, 16, 143, 18, 511, 20, 217, 22, 279, 24, 299, 25, 319, 26, 33, 27, 147, 28, 943, 30, 121, 32, 87, 34, 333, 35, 781, 36, 249, 38, 679, 40, 99, 42, 117, 44, 1463, 45, 697, 46, 187, 48, 207, 50, 219, 51, 639, 52