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A094150
Number of iterations of the sum of digits of the divisors of R(n) needed to reach 15, where R(n) = A002275.
0
5, 13, 12, 3, 11, 10, 15, 3, 14, 3, 5, 18, 13, 4, 18, 18, 5, 2, 4, 3, 12, 10, 21, 12, 18, 16, 11, 19, 20, 4, 6, 12, 13, 6, 6, 5, 3, 16, 5, 12, 12, 11, 18, 16, 18, 17, 12, 5, 12, 12, 18, 19, 14, 4, 5, 12, 18, 10, 16, 6, 13, 17, 21, 19, 6, 13, 19, 4, 3, 7, 15, 10, 21, 4, 18, 3, 5, 20, 11, 18
OFFSET
2,1
EXAMPLE
a(9)=3 because 111111111 -> 151 -> 8 -> 15.
a(1) does not exist because 1 -> 1 and never reaches 15.
CROSSREFS
Sequence in context: A089534 A116981 A222756 * A375275 A130502 A320814
KEYWORD
less,nonn,base
AUTHOR
Jason Earls, Jun 01 2004
EXTENSIONS
More terms from David Wasserman, May 22 2007
STATUS
approved