

A132133


Number of ndigit "Punctual Birds" (cf. A131881).


6




OFFSET

0,2


COMMENTS

The number of ndigit "Early Birds" is 9*10^(n1)  A132133(n), which is 0, 45, 630, 6896, 73059, 757755, 7773854, ... for n = 1, 2, ...
Here a(0) = 1 corresponds to the number 0 which is punctual in the sense that it does not occur before position 0, and which may be considered to have 0 digits for convenience: The index of 10^n in A131881 is then Sum_{k=0..n} a(k).  M. F. Hasler, Oct 25 2019


LINKS

Table of n, a(n) for n=0..7.


EXAMPLE

a(2) = 45 because there are 45 2digit Punctual Birds (10, 11, 1320, 22, 2430, 33, 3540, 44, 4650, 55, 5760, 66, 6870, 77, 79, 80, 88 and 90)


CROSSREFS

Cf. A033307, A117804, A116700, A131881, A132131, A132132.
Sequence in context: A316108 A026092 A054628 * A009410 A290358 A030113
Adjacent sequences: A132130 A132131 A132132 * A132134 A132135 A132136


KEYWORD

base,nonn,more


AUTHOR

Graeme McRae, Aug 11 2007


EXTENSIONS

Extended to a(0) = 1 by M. F. Hasler, Oct 25 2019


STATUS

approved



