A173098
a(1)=1, a(2)=2, a(n)=2*a(n-2)*a(n-1)-a(n-1).
Original entry on oeis.org
1, 2, 2, 6, 18, 198, 6930, 2737350, 37936933650, 207693292716721350, 15758493330480878908260133650, 6545866736124132578837836330405530973356721350
Offset: 1
-
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 *)
A173099
a(1)=1, a(2)=3, a(n)=2*a(n-2)*a(n-1)-a(n-2)-a(n-1).
Original entry on oeis.org
1, 3, 2, 7, 19, 240, 8861, 4244179, 75211087198, 638418558490509507, 96032307742263928939148386067, 122617614954666266094919182714589930973500782364
Offset: 1
-
a=1;b=3;lst={a,b};Do[c=2*a*b-a-b;AppendTo[lst,c];a=b;b=c,{n,12}];lst
nxt[{a_,b_}]:={b,2*a*b-a-b}; NestList[nxt,{1,3},12][[All,1]] (* Harvey P. Dale, Jan 03 2022 *)
A173100
a(1)=2, a(2)=2, a(n)=2*a(n-2)*a(n-1)-a(n-2)-a(n-1).
Original entry on oeis.org
2, 2, 4, 10, 66, 1244, 162898, 405126082, 131988051722292, 106943604398142563191514, 28230555977340642743866391573263146370, 6038154820760673175690853635193471535603786459126013221470476
Offset: 1
-
a=2;b=2;lst={a,b};Do[c=2*a*b-a-b;AppendTo[lst,c];a=b;b=c,{n,12}];lst
Showing 1-3 of 3 results.