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A082569
a(1)=2; a(n)=ceiling(n*(a(n-1)-1/a(n-1))).
1
2, 3, 8, 32, 160, 960, 6720, 53760, 483840, 4838400, 53222400, 638668800, 8302694400, 116237721600, 1743565824000, 27897053184000, 474249904128000, 8536498274304000, 162193467211776000, 3243869344235520000
OFFSET
1,1
FORMULA
a(1)=2 a(2)=3 and for n>2, a(n)= 4*n!/3.
a(n) = A090802(n, n-3) for n > 2. - Ross La Haye, Sep 26 2005
MATHEMATICA
nxt[{n_, a_}]:={n+1, Ceiling[(n+1)(a-1/a)]}; Transpose[NestList[nxt, {1, 2}, 20]][[2]] (* Harvey P. Dale, May 30 2015 *)
CROSSREFS
Equals 4 * A002301.
Sequence in context: A340935 A162074 A162052 * A340495 A084908 A078742
KEYWORD
nonn
AUTHOR
Benoit Cloitre, May 06 2003
STATUS
approved