A050708 - OEIS

%I #13 Oct 18 2019 17:00:27

%S 32,62,63,64,69,77,98,100,102,105,110,117,171,182,186,190,195,200,217,

%T 230,234,240,246,248,270,324,354,381,388,392,400,405,410,430,436,438,

%U 444,455,456,474,481,482,483,490,528,540,568,576,582,584,598,605,625

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

%e 182 is a term:

%e Iteration 1: 182 = 2*7*13 so 182 + (2+7+13) = 182 + 22 = 204 and composite.

%e Iteration 2: 204 = 2*2*3*17 so 204 + (2+2+3+17) = 204 + 24 = 228 and composite.

%e Iteration 3: 228 = 2*2*3*19 so 228 + (2+2+3+19) = 228 + 26 = 254 and composite.

%e Iteration 4: 254 = 2*127 so 254 + (2+127) = 254 + 129 = 383 and prime.

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

%K nonn

%O 1,1

%A _Patrick De Geest_, Aug 15 1999

%E Name edited by _Michel Marcus_, Oct 18 2019