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 A221002 The Wiener index of the nanostar dendrimer G[n], defined pictorially in the Karbasioun-Ashrafi reference. 1
 21558, 141686, 825078, 4438006, 22578678, 110311926, 522899958, 2422104566, 11019370998, 49421451766, 219106574838, 962208334326, 4192177750518, 18142557897206, 78066631049718, 334254292599286, 1424972878709238, 6051724204704246, 25614248465924598, 108086444576211446, 454863674100679158 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Table of n, a(n) for n=0..20. A. Karbasioun and A. R. Ashrafi, Wiener and detour indices of a new type of nanostar dendrimers, Macedonian J. of Chemistry and Chemical Engineering 28 (2009) 49-54. Index entries for linear recurrences with constant coefficients, signature (13,-64,148,-160,64). FORMULA a(n) = 502 + 2^(n+6)*5*(14*n+53)+4^(n+6)*(5n+1). G.f.: -2*(84672*x^4-205344*x^3+181436*x^2-69284*x+10779) / ((x-1)*(2*x-1)^2*(4*x-1)^2). [Colin Barker, Jan 01 2013] MAPLE a := proc (n) options operator, arrow: 502+5*2^(n+6)*(14*n+53)+4^(n+6)*(5*n+1) end proc; :seq(a(n), n = 0 .. 20); MATHEMATICA LinearRecurrence[{13, -64, 148, -160, 64}, {21558, 141686, 825078, 4438006, 22578678}, 30] (* Harvey P. Dale, Jul 20 2019 *) CROSSREFS Cf. A221003. Sequence in context: A063388 A252393 A211236 * A190470 A113620 A074812 Adjacent sequences: A220999 A221000 A221001 * A221003 A221004 A221005 KEYWORD nonn,easy AUTHOR Emeric Deutsch, Dec 28 2012 STATUS approved

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Last modified June 20 12:17 EDT 2024. Contains 373527 sequences. (Running on oeis4.)