A221003 The hyper-Wiener index of the nanostar dendrimer G[n], defined pictorially in the Karbasioun-Ashrafi reference.

192133, 1790789, 13716357, 92392837, 568494213, 3272754309, 17914312837, 94292506757, 481127721093, 2394073245829, 11669512054917, 55910670854277, 264011366000773, 1231270134409349, 5680970473662597, 25967383211403397

Offset

0,1

Links

Table of n, a(n) for n=0..15.

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 (19,-150,636,-1560,2208,-1664,512).

Formula

a(n) = -6011 + 2^n*(11200*n^2 + 5920*n - 177792) + 4^n*(102400*n^2 + 51200*n + 375936).

G.f.: (7432704*x^6 -23912064*x^5 +31269536*x^4 -21796184*x^3 +8511316*x^2 -1859738*x +192133) / ((x-1)*(2*x-1)^3*(4*x-1)^3). [Colin Barker, Jan 01 2013]

Maple

a := proc (n) options operator, arrow: -6011+2^n*(11200*n^2+5920*n-177792)+4^n*(102400*n^2+51200*n+375936) end proc: seq(a(n), n = 0 .. 15);

Crossrefs

Cf. A221002.

Sequence in context: A256768 A186584 A178289 * A206619 A253522 A254420

Adjacent sequences: A221000 A221001 A221002 * A221004 A221005 A221006

Keyword

nonn,easy

Author

Emeric Deutsch, Dec 28 2012

Status

approved