A173098 - OEIS

A173098

a(1)=1, a(2)=2, a(n)=2*a(n-2)*a(n-1)-a(n-1).

1, 2, 2, 6, 18, 198, 6930, 2737350, 37936933650, 207693292716721350, 15758493330480878908260133650, 6545866736124132578837836330405530973356721350

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OFFSET

1,2

LINKS

MATHEMATICA

a=1; b=2; lst={a, b}; Do[c=2*a*b-b; AppendTo[lst, c]; a=b; b=c, {n, 12}]; lst

RecurrenceTable[{a[1]==1, a[2]==2, a[n]==2a[n-2]a[n-1]-a[n-1]}, a, {n, 14}] (* Harvey P. Dale, Jan 27 2012 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

STATUS

approved