OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..13
M. Chamberland and M. Martelli, Unbounded Orbits and Binary Digits, Grinnell College.
FORMULA
MATHEMATICA
RecurrenceTable[{a[n] == a[n-1]^2 + a[n-1]*a[n-2]^2 - a[n-2]^4, a[1] == 2, a[2] == 3}, a, {n, 1, 10}] (* G. C. Greubel, Aug 05 2018 *)
PROG
(PARI) {a(n) = if( n<1, 0, if( n<3, n+1, my(x = a(n-2)^2, y = a(n-1)); y^2 + x*y - x^2))};
(Magma) I:=[2, 3]; [n le 2 select I[n] else Self(n-1)^2 + Self(n-1)*Self(n-2)^2 - Self(n-2)^4: n in [1..10]]; // G. C. Greubel, Aug 05 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Aug 17 2014
STATUS
approved