OFFSET
0,2
COMMENTS
a(n) is the number of compositions of n when there are 10 types of each natural number. - Milan Janjic, Aug 13 2010
Apart from the first term, number of monic squarefree polynomials over F_11 of degree n. - Charles R Greathouse IV, Feb 07 2012
REFERENCES
A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.
LINKS
FORMULA
a(n) = 11a(n-1) + ((-1)^n)*C(1, 1-n).
a(n) = 10*11^(n-1); a(0)=1.
G.f.: (1-x)/(1-11x).
MATHEMATICA
Table[EulerPhi[11^n], {n, 0, 40}] (* Vladimir Joseph Stephan Orlovsky, Nov 10 2009 *)
PROG
(PARI) a(n)=round(11^n*10/11) \\ Charles R Greathouse IV, Feb 07 2012
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, May 29 2000
STATUS
approved