A055276 - OEIS

%I #21 Jun 13 2015 00:50:15

%S 1,10,110,1210,13310,146410,1610510,17715610,194871710,2143588810,

%T 23579476910,259374246010,2853116706110,31384283767210,

%U 345227121439310,3797498335832410,41772481694156510,459497298635721610

%N First differences of 11^n (A001020).

%C a(n) is the number of compositions of n when there are 10 types of each natural number. - _Milan Janjic_, Aug 13 2010

%C Apart from the first term, number of monic squarefree polynomials over F_11 of degree n. - _Charles R Greathouse IV_, Feb 07 2012

%D A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

%H Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Enumerative Formulas for Some Functions on Finite Sets</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (11).

%F a(n) = 11a(n-1) + ((-1)^n)*C(1, 1-n).

%F a(n) = 10*11^(n-1); a(0)=1.

%F G.f.: (1-x)/(1-11x).

%t Table[EulerPhi[11^n],{n,0,40}] (* _Vladimir Joseph Stephan Orlovsky_, Nov 10 2009 *)

%o (PARI) a(n)=round(11^n*10/11) \\ _Charles R Greathouse IV_, Feb 07 2012

%Y Cf. A001020.

%K easy,nonn

%O 0,2

%A _Barry E. Williams_, May 29 2000