|
| |
|
|
A062547
|
|
a(n) is least odd integer not a partial sum of 1, 3, ..., a(n-1).
|
|
3
| |
|
|
1, 3, 5, 7, 17, 19, 53, 55, 161, 163, 485, 487, 1457, 1459, 4373, 4375, 13121, 13123, 39365, 39367, 118097, 118099, 354293, 354295, 1062881, 1062883, 3188645, 3188647, 9565937, 9565939, 28697813, 28697815, 86093441, 86093443, 258280325
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Odd indexed terms = A048473 and even indexed terms a(2n) = a(2n-1)+2;
a(2*n)=A048473(n) and also, for n>0, a(2*n)=3*a(2*n-1)-4; a(2*n+1)=a(2*n)+2=A052919(n+1).
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (-1,3,3).
|
|
|
FORMULA
| G.f.: (1+4*x+5*x^2)/((1+x)*(1-3*x^2)); a(n) = -a(n-1)+3*a(n-2)+3*a(n-3) for n>2. a(n) = 2*3^((2*n+(-1)^n-1)/4)-(-1)^n. - Bruno Berselli, Jan 28 2011
|
|
|
EXAMPLE
| Partial sums of 1;3;5 are 1;3;4;5;6;8;9 and 7 is the least missing odd integer, hence the next term is 7.
|
|
|
MATHEMATICA
| Table[ -1+ 2 3^Floor[k/2]+2 Mod[k, 2], {k, 0, 36}]
|
|
|
CROSSREFS
| Cf. A048473, A062548.
Sequence in context: A092951 A001259 A087126 * A125739 A122853 A137258
Adjacent sequences: A062544 A062545 A062546 * A062548 A062549 A062550
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Wouter Meeussen (wouter.meeussen(AT)pandora.be), Jun 26 2001
|
| |
|
|
