A363254 Product_{n>=1} (1 + a(n)*x^n) = 1 + 1!!*x + 3!!*x^2 + 5!!*x^3 + 7!!*x^4 + ...

1, 3, 12, 93, 816, 9264, 122028, 1863849, 32001504, 614224272, 12989299596, 300599511744, 7550646317520, 204694926767040, 5955892801274796, 185160666502244433, 6125200081143892800, 214838236392631067424, 7963817560398871790604, 311101474513327693885056

Offset

1,2

Links

Table of n, a(n) for n=1..20.

Mathematica

A[m_, n_] := A[m, n] = Which[m == 1, (2 n - 1)!!, m > n >= 1, 0, True, A[m - 1, n] - A[m - 1, m - 1] A[m, n - m + 1]]; a[n_] := A[n, n]; a /@ Range[1, 20]

Crossrefs

Cf. A001147, A158094, A305868, A305870, A363255.

Sequence in context: A342395 A058337 A025503 * A368454 A263801 A078124

Adjacent sequences: A363251 A363252 A363253 * A363255 A363256 A363257

Keyword

nonn

Author

Ilya Gutkovskiy, May 23 2023

Status

approved