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A305032 a(0) = 0, a(1) = 1 and a(n) = 6*a(n-1)/(n-1) + 4*a(n-2) for n > 1. 2
0, 1, 6, 22, 68, 190, 500, 1260, 3080, 7350, 17220, 39732, 90552, 204204, 456456, 1012440, 2230800, 4886310, 10647780, 23094500, 49884120, 107343236, 230205976, 492156392, 1049212528, 2230928700, 4732273000, 10015777800, 21154820400, 44596287000, 93846099600 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Let a(0) = 0, a(1) = 1 and a(n) = 2*m*a(n-1)/(n-1) + k^2*a(n-2) for n > 1.

Then G.f. is x/(2*m) * d/dx ((1 + k*x)/(1 - k*x))^(m/k).

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..3000

FORMULA

a(n) = n*A305031(n)/6.

G.f.: x*sqrt(1-4*x^2)/(1-2*x)^3.

CROSSREFS

Cf. A100071, A304944, A305031.

Sequence in context: A027992 A271389 A247168 * A171495 A178706 A276779

Adjacent sequences:  A305029 A305030 A305031 * A305033 A305034 A305035

KEYWORD

nonn

AUTHOR

Seiichi Manyama, May 24 2018

STATUS

approved

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Last modified May 12 11:55 EDT 2021. Contains 343821 sequences. (Running on oeis4.)