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A050708 Composites c that reach a prime after 4 iterations of c-> c+sum of prime factors of c. 6
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

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.

Sequence in context: A130447 A116284 A138555 * A132300 A206371 A255561

Adjacent sequences:  A050705 A050706 A050707 * A050709 A050710 A050711

KEYWORD

nonn

AUTHOR

Patrick De Geest, Aug 15 1999

EXTENSIONS

Name edited by Michel Marcus, Oct 18 2019

STATUS

approved

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Last modified August 5 21:58 EDT 2020. Contains 336213 sequences. (Running on oeis4.)