A050708 Composites c that reach a prime after 4 iterations of c-> c+sum of prime factors of c.

32, 62, 63, 64, 69, 77, 98, 100, 102, 105, 110, 117, 171, 182, 186, 190, 195, 200, 217, 230, 234, 240, 246, 248, 270, 324, 354, 381, 388, 392, 400, 405, 410, 430, 436, 438, 444, 455, 456, 474, 481, 482, 483, 490, 528, 540, 568, 576, 582, 584, 598, 605, 625

Offset: 1

Author

Patrick De Geest, Aug 15 1999

Keywords

• nonn

Examples

			182 is a term:
Iteration 1: 182 = 2*7*13 so 182 + (2+7+13) = 182 + 22 = 204 and composite.
Iteration 2: 204 = 2*2*3*17 so 204 + (2+2+3+17) = 204 + 24 = 228 and composite.
Iteration 3: 228 = 2*2*3*19 so 228 + (2+2+3+19) = 228 + 26 = 254 and composite.
Iteration 4: 254 = 2*127 so 254 + (2+127) = 254 + 129 = 383 and prime.
		

Crossrefs

Cf. A050703, A050704, A050705, A050706, A050707, A050709, A050710.

Extensions

Name edited by Michel Marcus, Oct 18 2019