OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..11
J. A. Haddley, Doubling Hypercuboids, Preprint 2015.
FORMULA
a(n) = a(n-1)*(a(n-1)-1).
a(n) ~ c^(2^n), where c = 1.8401979467004699327247921093647566233474761412868967823409865843403604499... . - Vaclav Kotesovec, Dec 18 2014
MAPLE
A204321 := proc(n)
if n = 1 then
4;
else
procname(n-1)*(procname(n-1)-1) ;
end if;
end proc:
seq(A204321(n), n=1..10) ; # R. J. Mathar, Jan 19 2012
MATHEMATICA
Join[{a = 4}, Table[a = a^2 - a, {n, 9}]] (* Vladimir Joseph Stephan Orlovsky, Feb 24 2012 *)
RecurrenceTable[{a[1]==4, a[n] == a[n-1]*(a[n-1]-1)}, a, {n, 1, 10}] (* Vaclav Kotesovec, Dec 18 2014 *)
NestList[#^2-#&, 4, 10] (* Harvey P. Dale, Jun 20 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Daniel Chiverton, Jan 14 2012
STATUS
approved