A221004 - OEIS

%I #11 Jun 23 2023 10:52:03

%S 1437,4263,15675,68163,325779,1602483,7835379,37613427,176915571,

%T 816731763,3710601843,16633811571,73738101363,323845964403,

%U 1411137700467,6107956052595,26286286307955,112564798489203,479941662081651,2038504721744499,8628988563948147,36415869693198963,153263217907335795,643451990789063283,2695404780741722739,11268007106608890483

%N The Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Wang-Hua reference.

%H H. Wang and H. Hua, <a href="https://chalcogen.ro/497_Wang.pdf">Computing the second- and third- connectivity index of an infinite class of dendrimer nanostars</a>, Digest J. Nanomaterials and Biostructures, 5 (2010) 497-502.

%H L. Yang and H. Hua, <a href="https://oam-rc.inoe.ro/articles/modified-terminal-wiener-index-of-a-type-of-dendrimer-nanostars/fulltext">Modified terminal Wiener index of a type of dendrimer nanostars</a>, Optoelectronics and Advanced Materials - Rapid Communications, 5 (2011) 160-163.

%F a(n) = 627 + 2^n*(936*n+1602)+4^n*(432*n-792).

%F G.f.: 3*(479-4806*x+17408*x^2-25152*x^3+13952*x^4)/((1-x)*(1-2*x)^2*(1-4*x)^2). - _Bruno Berselli_, Dec 30 2012

%p a := proc (n) options operator, arrow: 627+2^n*(936*n+1602)+4^n*(432*n-792) end proc: seq(a(n), n = 0 .. 25);

%Y Cf. A221005.

%K nonn,easy

%O 0,1

%A _Emeric Deutsch_, Dec 29 2012