

A239419


Numbers that end in the trivial cycle (0) under the rule: next term = product of the last three digits of the concatenated preceding terms.


5



0, 3, 5, 7, 8, 10, 15, 16, 17, 20, 25, 30, 33, 35, 36, 40, 41, 45, 50, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 63, 65, 67, 70, 74, 75, 76, 77, 78, 79, 80, 84, 85, 88, 89, 90, 95, 97, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 115, 116, 117, 120, 123, 125, 130, 132, 135, 136, 140, 145, 150, 151, 152, 153, 154, 155, 156, 157, 158
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OFFSET

1,2


COMMENTS

Additional rule: As long as there are less than k=3 digits in the sequence, the first digit is repeated as often as necessary, e.g. 3 => 3*3*3 = 27 => 3*2*7 = 42 => 7*4*2 = 56 => 2*5*6 = 60 => 6*6*0 = 0 => 6*0*0 => 0, ...
See A238984 for more details, motivation and links.


LINKS



PROG

(PARI) is_A239419(n) = !A238984(99, n) \\ Here, the somewhat arbitrary value 99 (number of iterations before checking for 0) should be sufficiently large for small n, but might need to be increased for larger starting values n.


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



