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A320274
Arrange ternary integers in lexicographic order. Put the order number for each term when their values are interpreted in base 3/2 (starting from 0).
1
0, 1, 3, 2, 5, 9, 6, 11, 17, 4, 7, 12, 10, 15, 23, 19, 27, 37, 14, 21, 29, 25, 34, 46, 40, 53, 68, 8, 13, 20, 16, 24, 33, 28, 39, 51, 22, 31, 43, 36, 48, 63, 56, 71, 88, 45, 59, 75, 66, 83, 103, 93, 114, 138, 32, 44, 57, 49, 64, 81, 72, 90, 111, 60, 77, 96, 85, 106, 129, 117, 142, 169, 100, 122, 148, 135, 162
OFFSET
0,3
COMMENTS
Every nonnegative integer appears exactly once.
EXAMPLE
The ternary integers are: 0, 1, 2, 10, 11, 12, 20, 21, 22, 100 and so on. The values of these numbers interpreted in base 3/2 are 0, 1, 2, 1.5, 2.5, 3.5, 3, 4, 5, 2.25 and so on. The values in ascending order are: 0, 1, 1.5, 2, 2.25, 2.5 and so on. Consider n=4. The corresponding ternary integer is 11 with the value 2.5. 2.5 is the fifth positive value on the list, thus a(4) = 5.
CROSSREFS
The inverse is sequence A320273.
Cf. A024629.
Sequence in context: A254331 A210742 A175056 * A333398 A257705 A257878
KEYWORD
nonn,base
AUTHOR
Tanya Khovanova and PRIMES STEP Junior group, Oct 08 2018
STATUS
approved