A156122 a(n) = P_{2n}(sqrt(2))/sqrt(2) (see A155100).

1, 6, 192, 15216, 2249472, 534437376, 186227300352, 89472023771136, 56685374949752832, 45789401925385322496, 45932606279820521766912, 56019030070478949980307456, 81629508898089483953705582592, 140066108036622450865749167702016, 279529326198310211796977967402319872

Offset: 0

Author

N. J. A. Sloane, Nov 05 2009

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 0..207

Crossrefs

Cf. A155100.

Programs

Mathematica

p[n_, u_]:= D[Tan[x], {x, n}] /. Tan[x] -> u /. Sec[x] -> Sqrt[1 + u^2] // Expand; p[-1, u_] = 1;  Table[p[n, Sqrt[2]]/Sqrt[2], {n, -1, 100}][[2 ;; ;; 2]] (* G. C. Greubel, Sep 28 2018 *)