

A165442


Start with m, repeatedly find sum of prime factors until we reach a fixed point, then compute sum of numbers in trajectory except for m and the fixed point. If the resulting sum equals m, adjoin m to the sequence.


0




OFFSET

1,1


COMMENTS

No further terms below 10^13. Note that if the sum of the prime factors of a composite number equals itself, then it can only be 4.


LINKS



EXAMPLE

Take 20 as example, the sum of its prime factors is 9, then we move on until we get a prime, 9=3x3, 3+3=6, and 6=2x3, 2+3=5, add all the results in the process, 9+6+5=20. 20=9+6+5, 38=21+10+7, 74=39+16+8+6+5.


CROSSREFS



KEYWORD

nonn,more,bref


AUTHOR

K. T. Lee (7x3(AT)21cn.com), Sep 19 2009


EXTENSIONS



STATUS

approved



