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A055657
If a(n) is prime, a(n+1) = a(n) followed by a 1; if a(n) is composite, a(n+1) = concatenation of distinct prime factors of a(n).
2
0, 1, 11, 111, 337, 3371, 33711, 317661, 3195573, 33134361, 313849599, 3714945219, 3412771691, 7487538813, 38359316903, 1311540119013, 3837735218627, 38377352186271, 371907319435931, 715238131259661, 3907388967590269, 72910334611861889, 729103346118618891
OFFSET
0,3
COMMENTS
Is the sequence eventually cyclic? - Charles R Greathouse IV, Apr 27 2010
LINKS
MAPLE
a:= proc(n) option remember; `if`(n=0, 0, (t-> parse(cat(`if`(isprime(t)
or t<2, [t, 1][], sort([numtheory[factorset](t)[]])[]))))(a(n-1)))
end:
seq(a(n), n=0..30); # Alois P. Heinz, Apr 03 2022
CROSSREFS
Cf. A049121.
Sequence in context: A336523 A209233 A062095 * A049121 A143573 A248039
KEYWORD
nonn,base
AUTHOR
Harvey P. Dale, Jun 08 2000
STATUS
approved