The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A305265 a(n) = 12*2^n + 62. 4
 74, 86, 110, 158, 254, 446, 830, 1598, 3134, 6206, 12350, 24638, 49214, 98366, 196670, 393278, 786494, 1572926, 3145790, 6291518, 12582974, 25165886, 50331710, 100663358, 201326654, 402653246, 805306430, 1610612798, 3221225534, 6442451006, 12884901950, 25769803838, 51539607614, 103079215166, 206158430270 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS a(n) (n>=1) is the number of vertices of the first type of dendrimer nanostar G[n], shown pictorially in the Iranmanesh et al. reference (Fig. 1). LINKS Colin Barker, Table of n, a(n) for n = 0..1000 A. Iranmanesh, N. A. Gholami, Computing the Szeged index of two type dendrimer nanostars, Croatica Chemica Acta, 81, No. 2, 2008, 299-303. Index entries for linear recurrences with constant coefficients, signature (3,-2). FORMULA From Colin Barker, May 30 2018: (Start) G.f.: 2*(37 - 68*x) / ((1 - x)*(1 - 2*x)). a(n) = 3*a(n-1) - 2*a(n-2) for n>1. (End) MAPLE seq(12*2^n+62, n = 0..40); PROG (PARI) Vec(2*(37 - 68*x) / ((1 - x)*(1 - 2*x)) + O(x^40)) \\ Colin Barker, May 30 2018 CROSSREFS Cf. A305266, A305267, A305268. Sequence in context: A136948 A137139 A095569 * A055111 A020203 A295158 Adjacent sequences:  A305262 A305263 A305264 * A305266 A305267 A305268 KEYWORD nonn,easy AUTHOR Emeric Deutsch, May 29 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 18 16:27 EST 2020. Contains 331011 sequences. (Running on oeis4.)