A132134 Base 3 "Punctual Bird" numbers: write the natural numbers, base 3, in a string 12101112202122100101102... Sequence gives numbers which do not occur in the string ahead of their natural place.

1, 2, 3, 4, 6, 9, 11, 15, 18, 27, 29, 30, 32, 33, 35, 42, 45, 54, 60, 81, 83, 86, 87, 89, 92, 95, 96, 98, 99, 101, 104, 105, 107, 123, 126, 135, 141, 153, 162, 243, 245, 248, 249, 251, 252, 254, 257, 258, 260, 261, 263, 266, 267, 269, 275, 276, 278, 285, 287, 288

Offset

1,2

Links

Table of n, a(n) for n=1..60.

Example

a(5)=6 because 6 (20, base 3) is the fifth number that appears first in its "natural" place in the string of concatenated base-3 numbers.

Crossrefs

Cf. A033307, A117804, A116700, A131881, A132131, A132132, A132133, A132135.

Sequence in context: A331444 A039865 A304428 * A027594 A130899 A007210

Adjacent sequences: A132131 A132132 A132133 * A132135 A132136 A132137

Keyword

nonn,base

Author

Graeme McRae, Aug 11 2007

Status

approved