A330518 Expansion of e.g.f. Product_{k>=1} (sec(x^k) + tan(x^k)).

1, 1, 3, 14, 77, 536, 4471, 41474, 437737, 5206120, 67098091, 944705662, 14495605277, 237203399044, 4162492013135, 78089687760842, 1545654292223825, 32385137447167280, 716473190874986323, 16611710217097325366, 404119023609893926405

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Mathematica

nmax = 20; CoefficientList[Series[Product[(Sec[x^k] + Tan[x^k]), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!

Crossrefs

Cf. A000111, A203716, A229263, A270294, A270662, A270663, A270664, A270665, A270666, A330514, A330515, A330516, A330517.

Sequence in context: A048779 A369477 A052186 * A228656 A244507 A367016

Adjacent sequences: A330515 A330516 A330517 * A330519 A330520 A330521

Keyword

nonn

Author

Ilya Gutkovskiy, Dec 17 2019

Status

approved