|
Search: id:A126645
|
|
|
| A126645 |
|
a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3,4 and 5, at least one of digits 6,7 and at least one of digits 8,9. |
|
+0
2
|
|
| 5, 21, 77, 261, 845, 2661, 8237, 25221, 76685, 232101, 700397, 2109381, 6344525, 19066341, 57264557, 171924741, 516036365, 1548633381, 4646948717, 13942943301, 41833024205, 125507461221, 376539160877, 1129651037061
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
|
|
FORMULA
|
a(n)=4*3^n-4*2^n+1
|
|
EXAMPLE
|
a(8)=25221
|
|
MAPLE
|
f:=n->4*3^n-4*2^n+1;
|
|
CROSSREFS
|
Cf. A125630, A125948, A125947, A125946, A125945, A125940, A125909, A125908, A125880, A125897, A125904, A125858.
Sequence in context: A099899 A055280 A079923 this_sequence A026329 A014533 A134770
Adjacent sequences: A126642 A126643 A126644 this_sequence A126646 A126647 A126648
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Aleksandar M. Janjic and Milan R. Janjic (agnus(AT)blic.net), Feb 08 2007
|
|
|
Search completed in 0.002 seconds
|
