|
Search: id:A060531
|
|
|
| A060531 |
|
a(n)=18a(n-1)-80a(n-2), a(0)=1, a(1)=9. G.f.: (1-9x)/((1-8x)(1-10x)). E.g.f. exp(9x)cosh(x). a(n)=8^n/2+9^n/3. |
|
+0
5
|
|
| 1, 9, 82, 756, 7048, 66384, 631072, 6048576, 58388608, 567108864, 5536870912, 54294967296, 534359738368, 5274877906944, 52199023255552, 517592186044416, 5140737488355328, 51125899906842624, 509007199254740992
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Binomial transform of A081190. 9th binomial transform of (1,0,1,0,1,......), A059841.
Number of strings of n decimal digits that contain an even number of 0's. E.g. For n = 1 there are 9 strings: {1 2 3 4 5 6 7 8 9}; for n = 2 there are 82: {00 11 12 13 14 15 16 17 18 19 21 ... 96 97 98 99}.
|
|
FORMULA
|
a(1)=9, a(n) = 8*a(n-1) + 10^(n-1).
|
|
MAPLE
|
A060531 := proc(n) option remember: if n = 1 then RETURN(9) fi: 8*A060531(n-1) + 10^(n-1): end: for n from 1 to 40 do printf(`%d, `, A060531(n)) od:
|
|
CROSSREFS
|
Cf. A081192.
Sequence in context: A099371 A068109 A081191 this_sequence A045741 A110567 A041146
Adjacent sequences: A060528 A060529 A060530 this_sequence A060532 A060533 A060534
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
njas, Apr 12 2001
|
|
EXTENSIONS
|
More terms from James A. Sellers (sellersj(AT)math.psu.edu) and Jason Earls (zevi_35711(AT)yahoo.com), Apr 12 2001
Additional comments from Paul Barry (pbarry(AT)wit.ie), Mar 11 2003
|
|
|
Search completed in 0.002 seconds
|
