A132135 Number of base-3 "Punctual Birds" with n base-3 digits.

2, 3, 4, 10, 20, 51, 133, 359, 975, 2700, 7506, 20962, 58968, 166170

Offset

1,1

Links

Table of n, a(n) for n=1..14.

Example

a(2)=3 because 3 of the six 2-digit base-3 numbers appear in their natural order in the string of concatenated base-3 numbers. These 3 numbers are 3, 4 and 6 (10, 11 and 20 base-3).

Crossrefs

Cf. A132134.

Sequence in context: A085932 A214283 A135056 * A131871 A132446 A332838

Adjacent sequences: A132132 A132133 A132134 * A132136 A132137 A132138

Keyword

nonn,base

Author

Graeme McRae, Aug 11 2007

Status

approved