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A050709 Composites c that reach a prime after 5 iterations of c-> c+sum of prime factors of c. 6
49, 50, 52, 56, 84, 88, 169, 176, 180, 198, 220, 302, 322, 336, 339, 363, 364, 372, 387, 402, 406, 407, 424, 429, 434, 442, 492, 494, 508, 552, 553, 562, 589, 612, 628, 633, 650, 708, 724, 744, 760, 788, 816, 819, 843, 848, 860, 861, 862, 870, 872, 896, 918 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

49 is a term:

Iteration 1: 49 = 7*7 so 49 + (7+7) = 49 + 14 = 63 and composite.

Iteration 2: 63 = 3*3*7 so 63 + (3+3+7) = 63 + 13 = 76 and composite.

Iteration 3: 76 = 2*2*19 so 76 + (2+2+19) = 76 + 23 = 99 and composite.

Iteration 4: 99 = 3*3*11 so 99 + (3+3+11) = 99 + 17 = 116 and composite.

Iteration 5: 116 = 2*2*29 so 116 + (2+2+29) = 116 + 33 = 149 and prime.

CROSSREFS

Cf. A050703, A050704, A050705, A050706, A050707, A050708, A050710.

Sequence in context: A198435 A165870 A266803 * A037412 A176309 A080201

Adjacent sequences:  A050706 A050707 A050708 * A050710 A050711 A050712

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 November 18 10:08 EST 2019. Contains 329261 sequences. (Running on oeis4.)