A173093 a(1)=1, a(2)=3, a(n)=a(n-2)*a(n-1)-a(n-2).

1, 3, 2, 3, 4, 9, 32, 279, 8896, 2481705, 22077238784, 54789193873965015, 1209594115938395614939902976, 66272686526956073137307690185435702644419625

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Feb 09 2010

Keywords

• nonn

Programs

Mathematica

a=1;b=3;lst={a,b};Do[c=a*b-a;AppendTo[lst,c];a=b;b=c,{n,14}];lst
RecurrenceTable[{a[1]==1,a[2]==3,a[n]==a[n-2]a[n-1]-a[n-2]},a,{n,20}] (* Harvey P. Dale, Feb 09 2014 *)