The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A224423 The Wiener index of the Micelle-like chiral dendrimer G[n] defined pictorially in the Hassan Yousefi-Azari et al. reference. 1
 24485, 120741, 613541, 3078309, 15070373, 71955621, 336069797, 1540900005, 6958417061, 31031755941, 136961328293, 599275078821, 2603021763749, 11236212212901, 48242297406629, 206161018094757, 877415731561637, 3720758807233701, 15727438348682405 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS a(0) has been checked by the direct computation of the Wiener index (using Maple). LINKS Table of n, a(n) for n=0..18. H. Yousefi-Azari, A. R. Ashrafi, and M. H. Khalifeh, Wiener index of micelle-like chiral dendrimers, Studia UBB, Chemia, 55, No. 4, 125-130, 2010. Index entries for linear recurrences with constant coefficients, signature (13,-64,148,-160,64). FORMULA a(n) = 1189 + 15616*2^n + 7680*4^n + 12288*n*4^n + 4224*n*2^n (agrees with Theorem 2 of the Yousefi-Azari et al. reference). G.f.: (24485-197564*x+610948*x^2-794080*x^3+366912*x^4)/((1-x)*(1-2*x)^2*(1-4*x)^2). [Bruno Berselli, Apr 06 2013] MAPLE a := proc (n) options operator, arrow: 1189 + 15616*2^n + 4224*2^n*n + 12288*4^n*n + 7680*4^n end proc: seq(a(n), n = 0 .. 18); MATHEMATICA CoefficientList[Series[(24485 - 197564 x + 610948 x^2 - 794080 x^3 + 366912 x^4)/((1 - x) (1 - 2 x)^2 (1 - 4 x)^2), {x, 0, 20}], x] (* Bruno Berselli, Apr 06 2013 *) CROSSREFS Cf. A224424. Sequence in context: A083621 A083622 A237207 * A356355 A258441 A244150 Adjacent sequences: A224420 A224421 A224422 * A224424 A224425 A224426 KEYWORD nonn,easy AUTHOR Emeric Deutsch, Apr 06 2013 STATUS approved

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

Last modified June 14 02:27 EDT 2024. Contains 373392 sequences. (Running on oeis4.)