A170938 4^n+2^n+2.

4, 8, 22, 74, 274, 1058, 4162, 16514, 65794, 262658, 1049602, 4196354, 16781314, 67117058, 268451842, 1073774594, 4295032834, 17180000258, 68719738882, 274878431234, 1099512676354, 4398048608258, 17592190238722, 70368752566274, 281474993487874, 1125899940397058

Offset: 0

Author

N. J. A. Sloane, Feb 13 2010

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (7,-14,8).

Programs

Mathematica

Table[4^n+2^n+2,{n,0,30}] (* or *) LinearRecurrence[{7,-14,8},{4,8,22},30] (* Harvey P. Dale, Jan 10 2013 *)

Formula

a(n)= 7*a(n-1) -14*a(n-2) +8*a(n-3). G.f.: 2*(2-10*x+11*x^2)/((1-x) * (2*x-1) * (4*x-1)). [From R. J. Mathar, Feb 15 2010]