OFFSET
1,3
MATHEMATICA
RecurrenceTable[{a[1]==a[2]==1, a[3]==2, a[n]==(a[n-1]+a[n-2])a[n-3]-a[n-1]}, a, {n, 20}] (* Harvey P. Dale, Jul 23 2018 *)
PROG
(PARI) a(n) = if(n<4, fibonacci(n), (a(n-1)+a(n-2))*a(n-3)-a(n-1)) \\ Altug Alkan, Oct 08 2015
(Magma) I:=[1, 1, 2]; [n le 3 select I[n] else (Self(n-1)+ Self(n-2))*Self(n-3)-Self(n-1): n in [1..20]]; // Vincenzo Librandi, Oct 09 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Gianmarco Giordano, Oct 08 2015
EXTENSIONS
More terms from Altug Alkan, Oct 08 2015
STATUS
approved