|
Search: id:A007091
|
|
|
| A007091 |
|
Numbers in base 5.
(Formerly M0595)
|
|
+0
25
|
|
| 0, 1, 2, 3, 4, 10, 11, 12, 13, 14, 20, 21, 22, 23, 24, 30, 31, 32, 33, 34, 40, 41, 42, 43, 44, 100, 101, 102, 103, 104, 110, 111, 112, 113, 114, 120, 121, 122, 123, 124, 130, 131, 132, 133, 134, 140, 141, 142, 143, 144, 200, 201, 202, 203, 204, 210, 211, 212, 213
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
Contribution from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 25 2009: (Start)
Nonnegative integers with no decimal digit > 4.
Thus nonnegative integers in base 10 whose doubling by normal addition or multiplication requires no carry operation. (End)
It appears that this sequence corresponds to the numbers n for which twice the sum of digits of n is the sum of digits of 2*n. [From Remy Sigrist (remysigrist(AT)free.fr), Nov 22 2009]
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
FORMULA
|
a(0)=0 a(n)=10*a(n/5) if n==0 (mod 5) a(n)=a(n-1)+1 otherwise. - Benoit Cloitre, Dec 22, 2002
|
|
MATHEMATICA
|
Table[ FromDigits[ IntegerDigits[n, 5]], {n, 0, 60}]
|
|
PROGRAM
|
(PARI) a(n)=if(n<1, 0, if(n%5, a(n-1)+1, 10*a(n/5)))
|
|
CROSSREFS
|
Cf. A000042, A007088, A007089, A007090, A007092, A007093, A007094 & A007095.
Sequence in context: A098892 A037325 A037469 this_sequence A058185 A080897 A117383
Adjacent sequences: A007088 A007089 A007090 this_sequence A007092 A007093 A007094
|
|
KEYWORD
|
nonn,base,new
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com)
|
|
|
Search completed in 0.002 seconds
|
