A088608 a(1) = 1, a(n) = prime(n) if n is composite else a(n) = composite(n).

1, 6, 8, 7, 10, 13, 14, 19, 23, 29, 20, 37, 22, 43, 47, 53, 27, 61, 30, 71, 73, 79, 35, 89, 97, 101, 103, 107, 44, 113, 46, 131, 137, 139, 149, 151, 54, 163, 167, 173, 58, 181, 62, 193, 197, 199, 66, 223, 227, 229, 233, 239, 75, 251, 257, 263, 269, 271, 82, 281, 85, 293

Offset: 1

Author

Amarnath Murthy, Oct 16 2003

Keywords

• base
• nonn

Examples

			a(9) = 23 = prime(9).
		

Crossrefs

Cf. A088607.

Programs

Mathematica

Join[{1},Module[{nn=100,cmps},cmps=Select[Range[2nn],CompositeQ];Table[ If[ PrimeQ[n],cmps[[n]],Prime[n]],{n,2,nn}]]] (* Harvey P. Dale, May 22 2021 *)

Extensions

More terms from Ray Chandler, Oct 18 2003