login
A330159
The self-repeating start values of the iterative sequence A328680.
1
91711, 91712, 141691, 151481, 161271, 271161, 1310812, 5020232, 10117443, 11552816, 14118522, 14149412, 14821815, 31410828, 35523710, 41113743, 46211402, 84404483, 91186117
OFFSET
1,1
COMMENTS
This sequences lists the self-repeating starting values n for the iterative sequence defined in A328680 up to starting values of n = 10^8. Each number in this sequence, when acting as the starting value for the A328680 iteration, will be the first number repeated in the iteration. Note that the other numbers appearing in the iterative sequence for a given start value n will in general NOT be other entries of this sequence as the iteration depends critically on the start value of n itself. As can be seen these numbers are quite rare, there being only 19 entries for n up to 100 million. It is unknown if this is a finite or infinite sequence.
EXAMPLE
91711 is in the sequence as A040115(91711) = 8660, A053392(8660) = 14126, A053392(14126) = 5538, A053392(5538) = 10811, A053392(10811) = 1892, A053392(1892) = 91711, repeating the starting value 91711.
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, Dec 03 2019
STATUS
approved