The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A135294 a(n) = 3*a(n-1)+n if a(n-1) is not divisible by 2, or a(n) = a(n-1)/2 otherwise 1

%I

%S 1,4,2,1,7,26,13,46,23,78,39,128,64,32,16,8,4,2,1,22,11,54,27,104,52,

%T 26,13,66,33,128,64,32,16,8,4,2,1,40,20,10,5,56,28,14,7,66,33,146,73,

%U 268,134,67,253,812,406,203,665,2052,1026,513,1599,4858,2429,7350,11090

%N a(n) = 3*a(n-1)+n if a(n-1) is not divisible by 2, or a(n) = a(n-1)/2 otherwise

%C a(n)=a(0)*(3^(n-i))/(2^i) + c where c is in the range (0..sum(i*3^(n-i))). Sum(i*3^(n-i)) for i=1 to n equals A001793 (coefficients of Chebyshev polynomials). Max a(n) = 3^n*(a(0)/3^i*2^i + 9/4) - ((2*n+5)/4) which for large n gives max a(n) ~ 2.25*3^n - n/2. - _Ctibor O. Zizka_, Dec 26 2007

%Y Cf. A135287.

%K nonn

%O 1,2

%A _Ctibor O. Zizka_, Dec 04 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 17 22:14 EDT 2021. Contains 345086 sequences. (Running on oeis4.)