A173097 a(1)=1, a(2)=2, a(n)=2*a(n-2)*a(n-1)-a(n-2).

1, 2, 3, 10, 57, 1130, 128763, 291003250, 74940902830737, 43616092563357042787250, 6537258709293941644669222566000575763, 570259361950353096439107826720562074995499493885695588056250

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Feb 09 2010

Keywords

• nonn

Crossrefs

Cf. A173093, A173094, A173096

Programs

Mathematica

a=1;b=2;lst={a,b};Do[c=2*a*b-a;AppendTo[lst,c];a=b;b=c,{n,11}];lst
RecurrenceTable[{a[1]==1,a[2]==2,a[n]==2a[n-2]a[n-1]-a[n-2]},a,{n,15}] (* Harvey P. Dale, Sep 10 2016 *)