|
Search: id:A072105
|
|
|
| A072105 |
|
Let c(1)=x, c(n+1) = c(n)/2 + n if c(n) is even, c(n+1)= 2c(n) - n otherwise; then a(n)=c(n) for c(1)=3. |
|
+0
1
|
|
| 3, 5, 8, 7, 10, 10, 11, 15, 22, 20, 20, 21, 30, 28, 28, 29, 42, 38, 37, 55, 90, 66, 55, 87, 150, 100, 76, 65, 102, 80, 70, 66, 65, 102, 80, 70, 66, 65, 97, 160, 115, 194, 134, 105, 171, 302, 192, 138, 112, 100, 95, 144, 119, 190, 144, 122, 112, 108, 107, 160, 135
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
It seems that for any n, 2n <= a(n) <16n. If x=0,1,2,4 or 6 we have c(k+1)-c(k)=2 for k large enough and then lim k -> infinity c(k)/k=2. For x=3,5 and for any x >6 there is a conjectured constant 4 < C < 5 such that lim N -> infinity (1/N)*sum(k=1,N,c(k)/k) = C. Hence lim N -> infinity (1/N)*sum(k=1,N,a(k)/k) should be C=4.6...
|
|
EXAMPLE
|
a(1)=3 is odd hence a(2)=2*a(1)-1= 2*3-1 =5
|
|
CROSSREFS
|
Adjacent sequences: A072102 A072103 A072104 this_sequence A072106 A072107 A072108
Sequence in context: A021740 A110641 A121729 this_sequence A088509 A120098 A081859
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Benoit Cloitre (benoit7848c(AT)orange.fr), Jul 30 2002
|
|
|
Search completed in 0.002 seconds
|
