A224465 The Wiener index of the nanostar dendrimer defined pictorially as NS[n] in the Z. S. Irani reference.

8340, 12428, 26748, 76444, 268380, 1100508, 4959708, 23244764, 109587420, 512103388, 2360853468, 10733675484, 48188138460, 213973935068, 941242328028, 4107369456604, 17801289409500, 76697192899548, 328767224423388, 1403004800476124, 5963809931928540

Offset

0,1

References

Z. S. Irani, A. Karbasioun, Wiener index of a new type of nanostar dendrimer, Iranian J. Math. Chem., 2, 2011, 79-85.

Links

Table of n, a(n) for n=0..20.

Formula

a(n) = 9180 + 2^n*(2800*n+136)+4^n*(320*n-976).

G.f.: 4*(2085-23998*z+99736*z^2-177552*z^3+120384*z^4)/((1-z)*(1-2*z)^2*(1-4*z)^2).

Maple

a := proc (n) options operator, arrow: 9180+2^n*(2800*n+136)+4^n*(320*n-976) end proc: seq(a(n), n = 0 .. 20);

Crossrefs

Cf. A224466

Sequence in context: A124414 A124415 A233954 * A049357 A031947 A069402

Adjacent sequences: A224462 A224463 A224464 * A224466 A224467 A224468

Keyword

nonn

Author

Emeric Deutsch, Jul 12 2013

Status

approved