A012838 sec(sec(x)*tanh(x))=1+1/2!*x^2+9/4!*x^4+297/6!*x^6+14385/8!*x^8...

1, 1, 9, 297, 14385, 1207729, 143876601, 23841581337, 5193194291937, 1442318342390497, 497436148816555113, 208516037618871269001, 104439610892072605613073, 61591265237655555392072593

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Crossrefs

Sequence in context: A129934 A003303 A371252 * A216966 A211077 A211082

Adjacent sequences: A012835 A012836 A012837 * A012839 A012840 A012841

Keyword

nonn

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Status

approved