cp's OEIS Frontend

A260060 Least number such that exactly n iterations of A034690 are required to reach one of the fixed points, 1 or 15.

%I A260060 #18 Dec 23 2024 14:53:44
%S A260060 1,8,7,4,3,2,19,12,6,5,13,9,10,16,30,18,34,36,66,162,924,71820
%N A260060 Least number such that exactly n iterations of A034690 are required to reach one of the fixed points, 1 or 15.
%C A260060 Apart from the initial term a(1), the same as A094501.
%H A260060 E. Angelini et al., <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2015-November/015585.html">List the dividers, sum the digits</a>, SeqFan list, Nov. 2015 [Broken link]
%H A260060 Eric Angelini et al., <a href="/A086793/a086793.txt">List the dividers [sic], sum the digits</a>, lost messages reconstructed by _N. J. A. Sloane_, Dec 21 2024
%e A260060 The orbits are:
%e A260060   {1},
%e A260060   {8, 15},
%e A260060   {7, 8, 15},
%e A260060   {4, 7, 8, 15},
%e A260060   {3, 4, 7, 8, 15},
%e A260060   {2, 3, 4, 7, 8, 15},
%e A260060   {19, 11, 3, 4, 7, 8, 15},
%e A260060   {12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {10, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {16, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {34, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {36, 46, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {66, 36, 46, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {162, 66, 36, 46, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {924, 168, 102, 36, 46, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15},
%e A260060   {71820, 1104, 168, 102, 36, 46, 18, 30, 27, 22, 9, 13, 5, 6, 12, 19, 11, 3, 4, 7, 8, 15}
%o A260060 (PARI) a(n)=for(k=1,9e9, A086793(k)==n&&return(k))
%Y A260060 Cf. A034690, A086793, A094501, A095347.
%K A260060 nonn,base
%O A260060 0,2
%A A260060 _M. F. Hasler_, Nov 08 2015