A304387 a(n) = 27*2^n - 5.
22, 49, 103, 211, 427, 859, 1723, 3451, 6907, 13819, 27643, 55291, 110587, 221179, 442363, 884731, 1769467, 3538939, 7077883, 14155771, 28311547, 56623099, 113246203, 226492411, 452984827, 905969659, 1811939323, 3623878651, 7247757307, 14495514619, 28991029243, 57982058491
Offset: 0
Links
- Colin Barker, Table of n, a(n) for n = 0..1000
- M. B. Ahmadi and M. Sadeghimehr, Atom bond connectivity index of an infinite class NS1[n] of dendrimer nanostars, Optoelectronics and Advanced Materials, 4(7):1040-1042 July 2010.
- Ali Reza Ashrafi and Parisa Nikzad, Kekulé index and bounds of energy for nanostar dendrimers, Digest J. of Nanomaterials and Biostructures, 4, No. 2, 2009, 383-388.
- Index entries for linear recurrences with constant coefficients, signature (3,-2).
Programs
-
GAP
List([1..40],n->27*2^n-5); # Muniru A Asiru, May 13 2018
-
Maple
seq(27*2^n-5, n = 0 .. 40);
-
Mathematica
27*2^Range[0,40]-5 (* or *) LinearRecurrence[{3,-2},{22,49},40] (* Harvey P. Dale, Jan 12 2019 *) -
PARI
a(n) = 27*2^n - 5; \\ Altug Alkan, May 13 2018
-
PARI
Vec((22 - 17*x) / ((1 - x)*(1 - 2*x)) + O(x^40)) \\ Colin Barker, May 18 2018
Formula
From Colin Barker, May 18 2018: (Start)
G.f.: (22 - 17*x) / ((1 - x)*(1 - 2*x)).
a(n) = 3*a(n-1) - 2*a(n-2) for n>1.
(End)
Extensions
Offset changed by N. J. A. Sloane, May 13 2018
Comments