

A186750


a(0) = 3; thereafter, a(n) = a(n1)^2  3.


3




OFFSET

0,1


COMMENTS

This is to A001566 as 3 is to 2 (subtrahend). Unlike A001566, which begins with 4 consecutive primes, this sequence can never be prime after a(0) = 3, because the first two terms are both multiples of 3, hence all later terms are. This is the k = 3 row of the array A(k, 0) = 3, A(k, n) = A(k, n1)^2  k; and A001566 is the k = 2 row. A003096(n+1) is the k = 1 row.


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..11
Index entries for sequences of form a(n+1)=a(n)^2 + ...


FORMULA

a(n) ~ c^(2^n), where c = 2.3959550115176494685408322564302422183669584045032057908382914927198090627...  Vaclav Kotesovec, Dec 18 2014


MATHEMATICA

RecurrenceTable[{a[0] == 3, a[n] == a[n1]^2  3}, a, {n, 0, 10}] (* Vaclav Kotesovec, Dec 18 2014 *)
Drop[Abs[NestList[#^2  3 &, 0, 9]], 1] (* Alonso del Arte, Apr 08 2016 *)


CROSSREFS

Cf. A001566, A003096.
Sequence in context: A101142 A298679 A261885 * A203715 A249875 A308557
Adjacent sequences: A186747 A186748 A186749 * A186751 A186752 A186753


KEYWORD

nonn,easy


AUTHOR

Jonathan Vos Post, Feb 26 2011


STATUS

approved



