A182466 a(n) = 3a(n-1) - 2a(n-2) with a(0)=32 and a(1)=80.

32, 80, 176, 368, 752, 1520, 3056, 6128, 12272, 24560, 49136, 98288, 196592, 393200, 786416, 1572848, 3145712, 6291440, 12582896, 25165808, 50331632, 100663280, 201326576, 402653168, 805306352, 1610612720, 3221225456, 6442450928, 12884901872, 25769803760, 51539607536

Offset: 0

Author

Odimar Fabeny, Apr 30 2012

Keywords

• nonn
• easy

Comments

Number of vertices into building blocks of 3d objects with 8 vertices.

Examples

			a(0) = 8+16+8;
a(1) = 8+16+32+16+8;
a(2) = 8+16+32+64+32+16+8;
a(3) = 8+16+32+64+128+64+32+16+8.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (3, -2).

Crossrefs

Cf. A000045, A028399, A038578, A089143, A173033, A182461, A182462, A182464, A182465, A182467.

Programs

Mathematica

LinearRecurrence[{3,-2},{32,80},40] (* or *) Table[8(3*2^n-2),{n,40}] (* Harvey P. Dale, Aug 23 2012 *)
CoefficientList[Series[-((16 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)

Formula

a(n) = a(n-1)*2 + 16.

a(n) = 8*(3*2^n-2). - Harvey P. Dale, Aug 23 2012

G.f.: -((16(x-2))/(2*x^2-3*x+1)). - Harvey P. Dale, Aug 23 2012