A305164 a(n) = 28*2^n - 22.

6, 34, 90, 202, 426, 874, 1770, 3562, 7146, 14314, 28650, 57322, 114666, 229354, 458730, 917482, 1834986, 3669994, 7340010, 14680042, 29360106, 58720234, 117440490, 234881002, 469762026, 939524074, 1879048170, 3758096362, 7516192746, 15032385514, 30064771050, 60129542122, 120259084266, 240518168554

Offset

0,1

Comments

a(n) is the number of edges of the second type dendrimer nanostar NS2[n], defined pictorially in the Chen et al. reference (Fig. 1).

Links

Table of n, a(n) for n=0..33.

S. Chen and J. Yang, Second-order and third-order connectivity indices of dendrimer nanostars, International Mathematical Forum, 6, No, 5, 2011, 223-228.

Index entries for linear recurrences with constant coefficients, signature (3,-2).

Formula

G.f.: 2*(3 + 8*x)/((1 - x)*(1 - 2*x)). - Vincenzo Librandi, May 27 2018

Maple

seq(28*2^n-22, n = 0 .. 40);

Mathematica

Table[28 2^n - 22, {n, 0, 33}] (* Vincenzo Librandi, May 27 2018 *)
LinearRecurrence[{3, -2}, {6, 34}, 40] (* Harvey P. Dale, Jun 15 2023 *)

Prog

(Magma) [28*2^n-22: n in [0..33]]; // Vincenzo Librandi, May 27 2018

Crossrefs

Cf. A305163, A305165, A305166.

Sequence in context: A233510 A296808 A319199 * A067389 A281057 A341290

Adjacent sequences: A305161 A305162 A305163 * A305165 A305166 A305167

Keyword

nonn,easy

Author

Emeric Deutsch, May 27 2018

Status

approved