%I A055847
%S A055847 1,6,49,392,3136,25088,200704,1605632,12845056,102760448,822083584,
%T A055847 6576668672,52613349376,420906795008,3367254360064,26938034880512,
%U A055847 215504279044096,1724034232352768,13792273858822144,110338190870577152
%N A055847 A second order recursive sequence.
%C A055847 For n>=2, a(n) is equal to the number of functions f:{1,2,...,n}->{1,
               2,3,4,5,6,7,8} such that for fixed, different x_1, x_2 in {1,2,...,
               n} and fixed y_1, y_2 in {1,2,3,4,5,6,7,8} we have f(x_1)<>y_1 and 
               f(x_2)<> y_2. - Milan R. Janjic (agnus(AT)blic.net), Apr 19 2007
%D A055847 A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, 
               pps. 194-196.
%H A055847 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Enumerative Formulas 
               for Some Functions on Finite Sets</a>
%F A055847 a(n)=49*8^(n-2), a(0)=1, a(1)=6. a(n)=8a(n-1)+[(-1)^n]*C(2, 2-n); G.f.(x)=(1-x)^2/
               (1-8x).
%Y A055847 First differences of A055274. Cf. A001018.
%Y A055847 Sequence in context: A097299 A104170 A098306 this_sequence A143165 A008786 
               A046195
%Y A055847 Adjacent sequences: A055844 A055845 A055846 this_sequence A055848 A055849 
               A055850
%K A055847 easy,nonn
%O A055847 0,2
%A A055847 Barry E. Williams, Jun 03 2000
%E A055847 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 05 2000