0,1

An autocopy sequence: its first differences are the sequence itself. - Alexandre Wajnberg & Eric Angelini (alexandre.wajnberg(AT)ulb.ac.be), Sep 07 2005

For n>=1, a(n) is equal to the number of functions f:{1,2,...,n+2}->{1,2,3} such that for fixed, different x_1, x_2,...,x_n in {1,2,...,n+2} and fixed y_1, y_2,...,y_n in {1,2,3} we have f(x_i)<>y_i, (i=1,2,...,n). - Milan R. Janjic (agnus(AT)blic.net), May 10 2007

9 times powers of 2. [From Omar E. Pol (info(AT)polprimos.com), Dec 16 2008]

Index entries for sequences related to linear recurrences with constant coefficients

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

Tanya Khovanova, Recursive Sequences

a(n)= 9*2^n. G.f.: 9/(1-2*x).

a(n) = A118416(n+1,5) for n>4. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 27 2006

a(n)=2*a(n-1), n>0 ; a(0)=9 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 23 2008]

a(n) = A000079(n)*9 = A020714(n)*3. [From Omar E. Pol (info(AT)polprimos.com), Dec 16 2008]

with(finance):seq(futurevalue(9, 1, n), n=0..28); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 24 2009]

Row sums of (8, 1)-Pascal triangle A093565.

Cf. A000079, A020714. [From Omar E. Pol (info(AT)polprimos.com), Dec 16 2008]

Sequence in context: A051063 A162689 A033896 this_sequence A000547 A138900 A057373

Adjacent sequences: A005007 A005008 A005009 this_sequence A005011 A005012 A005013

nonn

N. J. A. Sloane (njas(AT)research.att.com).