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A122021 a(0) = 0, a(1) = 1, a(2) = 2; for n > 2, a(n) = a(n - 2) - (n - 1)*a(n - 3). 3
0, 1, 2, 1, -1, -7, -6, -1, 43, 47, 52, -383, -465, -1007, 4514, 5503, 19619, -66721, -73932, -419863, 1193767, 1058777, 10010890, -25204097, -14340981, -265465457, 615761444, 107400049, 7783328783, -17133920383, 4668727362 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..31.

MATHEMATICA

a[0] = 0; a[1] = 1; a[2] = 2; a[n_] := a[n] = a[n - 2] - (n - 1)*a[n - 3] Table[a[n], {n, 0, 30}]

CROSSREFS

Cf. A000898, A121966, A062267.

Sequence in context: A039760 A156882 A266309 * A303817 A158200 A220602

Adjacent sequences:  A122018 A122019 A122020 * A122022 A122023 A122024

KEYWORD

sign

AUTHOR

Roger L. Bagula, Sep 12 2006

EXTENSIONS

Edited by N. J. A. Sloane, Sep 12 2006

STATUS

approved

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Last modified May 22 07:19 EDT 2019. Contains 323478 sequences. (Running on oeis4.)