|
Search: id:A163403
|
|
|
| A163403 |
|
a(n) = 2*a(n-2) for n > 2; a(1) = 1, a(2) = 2. |
|
+0 4
|
|
| 1, 2, 2, 4, 4, 8, 8, 16, 16, 32, 32, 64, 64, 128, 128, 256, 256, 512, 512, 1024, 1024, 2048, 2048, 4096, 4096, 8192, 8192, 16384, 16384, 32768, 32768, 65536, 65536, 131072, 131072, 262144, 262144, 524288, 524288, 1048576, 1048576, 2097152, 2097152
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Equals A016116 without initial 1. Unsigned version of A152166.
Partial sums are in A136252. a(n) = A051032(n)-1.
Binomial transform is A078057, second binomial transform is A007070, third binomial transform is A102285, fourth binomial transform is A163350, fifth binomial transform is A163346.
|
|
FORMULA
|
a(n) = 2^(1/4*(2*n-1+(-1)^n)).
G.f.: x*(1+2*x)/(1-2*x^2).
a(n)=A131572(n). a(n)=A060546(n-1), n>1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 06 2009]
|
|
PROGRAM
|
(MAGMA) [ n le 2 select n else 2*Self(n-2): n in [1..43] ];
|
|
CROSSREFS
|
Cf. A000079 (powers of 2), A016116 (powers of 2 doubled up), A152166, A136252, A051032, A078057, A007070, A102285, A163350, A163346.
Sequence in context: A152166 A016116 A060546 this_sequence A120803 A000011 A022476
Adjacent sequences: A163400 A163401 A163402 this_sequence A163404 A163405 A163406
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jul 26 2009
|
|
|
Search completed in 0.002 seconds
|