A173097
a(1)=1, a(2)=2, a(n)=2*a(n-2)*a(n-1)-a(n-2).
Original entry on oeis.org
1, 2, 3, 10, 57, 1130, 128763, 291003250, 74940902830737, 43616092563357042787250, 6537258709293941644669222566000575763, 570259361950353096439107826720562074995499493885695588056250
Offset: 1
-
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 *)
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 *)
A309006
Product minus sum of the two previous terms in the sequence, with a(1) = 2 and a(2) = 5.
Original entry on oeis.org
2, 5, 3, 7, 11, 59, 579, 33523, 19375715, 649512684707, 12584772018235630083, 8173969059977170083865314925891, 102867537103924486790122812065087346778963284622979
Offset: 1
a(3) = a(1) * a(2) - (a(1) + a(2)) = 2 * 5 - (2 + 5) = 3.
-
I:=[2,5]; [n le 2 select I[n] else Self(n-1)*Self(n-2)-(Self(n-1)+Self(n-2)): n in [1..14]]; // Vincenzo Librandi, Jul 10 2019
-
RecurrenceTable[{x[n+1]==x[n]*x[n-1]-(x[n]+x[n-1]),x[1]==2,x[2]==5},x,{n,1,18}]
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 1-5 of 5 results.