%I M2093 N0828 #20 Sep 15 2024 14:12:03
%S 2,16,136,1232,12096,129024,1491840,18627840,250145280,3597834240,
%T 55212917760,900842342400,15575854694400,284549942476800,
%U 5477586392678400,110832202594713600,2351805274570752000
%N Generalized tangent numbers.
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D Letterio Toscano, Sulla Derivata di Ordinen della Funzione tg(x), Tohoku Math. J., 42 (1936), 144-154.
%o (PARI) a(n, k)=if(k<0,0,if(n==1 && k==1,1,if(k>n,0,(k-1)*a(n-1,k-1)+(k+1)*a(n-1,k+1))))
%o for(n=0,25,print1(a(n+4, n)",")) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006
%K nonn
%O 3,1
%A _N. J. A. Sloane_
%E More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006