A086221 Bisection of A086652.

13, 58, 244, 1000, 4048, 16288, 65344, 261760, 1047808, 4192768, 16774144, 67102720, 268423168, 1073717248, 4294918144, 17179770880, 68719280128, 274877513728, 1099510841344, 4398044938240, 17592182898688, 70368737886208

Offset: 1

Author

Marco Matosic, Jul 27 2003

Keywords

• nonn
• easy

Comments

(a(n)-2^(n-1))/2 = A006516(n+1).

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A006516, A086652.

Programs

Mathematica

Table[2^(2n+2)-3*2^(n-1),{n,30}] (* or *) nxt[{n_,a_}]:={n+1,4a+3*2^n}; NestList[nxt,{1,13},30][[All,2]] (* Harvey P. Dale, Nov 15 2021 *)

Formula

a(n) = 2^(2n+2)-3*2^(n-1).

a(n+1) = 4*a(n)+3*2^n.

Extensions

Edited and extended by David Wasserman, Feb 17 2005