|
Search: id:A072140
|
|
|
| A072140 |
|
The period length of the 'Reverse and Subtract' trajectory of n is greater than 1. |
|
+0
9
|
|
| 1012, 1023, 1034, 1045, 1067, 1078, 1089, 1100, 1122, 1133, 1144, 1155, 1177, 1188, 1199, 1210, 1232, 1243, 1254, 1265, 1287, 1298, 1320, 1342, 1353, 1364, 1375, 1397, 1408, 1430, 1452, 1463, 1474, 1485, 1507, 1518, 1540, 1562, 1573, 1584, 1595, 1606
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
'Reverse and Subtract' (cf. A072137) is defined by x -> |x - reverse(x)|. There is no number k > 0 such that |k - reverse(k)| = k, so 0 is the only period with length 1. Consequently this sequence consists of the numbers n such that repeated application of 'Reverse and Subtract' does not lead to a palindrome. It is an analogue of A023108, which uses 'Reverse and Add'. - A072141, A072142, A072143 give the numbers which generate periods of length 2, 14, 22 respectively.
|
|
EXAMPLE
|
1012 -> |1012 - 2101| = 1089 -> |1089 - 9801| = 8712 -> |8712 - 2178| = 6534 -> |6534 - 4356| = 2178 -> |2178 - 8712| = 6534; the period of the trajectory is 6534, 2178, and a palindrome is never reached.
|
|
CROSSREFS
|
Cf. A023108, A072137, A072141, A072142, A072143.
Adjacent sequences: A072137 A072138 A072139 this_sequence A072141 A072142 A072143
Sequence in context: A035125 A115769 A094946 this_sequence A080467 A023058 A022054
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jun 24 2002
|
|
|
Search completed in 0.002 seconds
|
