A002302 Generalized tangent numbers.

2, 16, 136, 1232, 12096, 129024, 1491840, 18627840, 250145280, 3597834240, 55212917760, 900842342400, 15575854694400, 284549942476800, 5477586392678400, 110832202594713600, 2351805274570752000

Offset: 3

Author

N. J. A. Sloane

Keywords

• nonn

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• Letterio Toscano, Sulla Derivata di Ordinen della Funzione tg(x), Tohoku Math. J., 42 (1936), 144-154.

Programs

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))))
for(n=0,25,print1(a(n+4, n)",")) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006