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A156122 a(n) = P_{2n}(sqrt(2))/sqrt(2) (see A155100). 2
1, 6, 192, 15216, 2249472, 534437376, 186227300352, 89472023771136, 56685374949752832, 45789401925385322496, 45932606279820521766912, 56019030070478949980307456, 81629508898089483953705582592, 140066108036622450865749167702016, 279529326198310211796977967402319872 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

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 *)

CROSSREFS

Cf. A155100.

Sequence in context: A182788 A232214 A012205 * A281501 A283884 A280552

Adjacent sequences: A156119 A156120 A156121 * A156123 A156124 A156125

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Nov 05 2009

STATUS

approved

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Last modified January 30 07:19 EST 2023. Contains 359939 sequences. (Running on oeis4.)