A101031 - OEIS

%I #3 Mar 30 2012 18:57:06

%S 0,0,1,0,1,7,0,1,15,58,0,1,31,196,601,0,1,63,634,2765,7656,0,1,127,

%T 1996,12265,44136,116929,0,1,255,6178,52925,248016,803383,2092112,0,1,

%U 511,18916,223801,1362096,5432161,16595776,43006401,0,1,1023,57514,932525

%N Triangle read by rows: T(n,k) = (1/k) times the number of functions from an n-element set into but not onto a k-element set.

%F T(n, k) = (A089072(n, k)-A019538(n, k))/k (where the two sequences are indexed as triangular arrays).

%e T(3,3) = (1/3)*[ #(functions into) - #(functions onto)] = (3^3 - 6)/3 = 7.

%K nonn,tabl

%O 0,6

%A _Clark Kimberling_, Nov 26 2004