OFFSET
0,2
COMMENTS
The next term is too large to be displayed here.
Old name was: Leg of primitive Pythagorean triangle generated by repeated application of the basic formula y(n) = 2*x(n-1)*y(n-1), x(1)=2, y(1)=1.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..11
FORMULA
a(n) = abs( Im((2+i)^(2^n)) ).
EXAMPLE
y(2)=24 since x(1)=3, y(1)=4 are the two legs of Pythagorean triangle obtained by p=2, q=1; second iteration p=3, q=4 gives 2*3*4=24.
MAPLE
a:= n-> abs(Im((2+I)^(2^n))):
seq(a(n), n=0..8); # Alois P. Heinz, Apr 25 2013
MATHEMATICA
Table[Abs[Im[(2 + I)^(2^n)]], {n, 0, 10}] (* G. C. Greubel, Jul 07 2017 *)
PROG
(PARI) a(n) = abs(imag((2+I)^(2^n))); \\ Joerg Arndt, Apr 25 2013
(Python)
from sympy import im, I
def a(n): return abs(im((2 + I)**(2**n)))
print([a(n) for n in range(11)]) # Indranil Ghosh, Jul 08 2017
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Carmine Suriano, Feb 04 2011
EXTENSIONS
Better name from Joerg Arndt, Apr 25 2013
STATUS
approved