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A062013
a(1) = 3, a(n) = a(n-1)^2 + 1.
4
3, 10, 101, 10202, 104080805, 10832813969448026, 117349858496668297583751115296677, 13770989289188072635789270799554901596999795308252284177727242330
OFFSET
1,1
COMMENTS
Define f(n, c) := x - Sum_{k>=0} A088674(k)/(2*x)^(2*k+1) where x = c^(2^n). Then a(n) = f(n, 1.78050350...). - Michael Somos, Jun 07 2021
LINKS
FORMULA
a(n) ~ c^(2^n), where c = 1.78050350352842911667602268320603615359... - Vaclav Kotesovec, Sep 20 2013
EXAMPLE
a(4) = a(3)^2 +1 = 101^2 +1 =10202
MATHEMATICA
NestList[#^2+1&, 3, 10] (* Harvey P. Dale, Feb 21 2013 *)
a[ n_] := If[n < 2, 3 Boole[n == 1], A062013[n - 1]^2 + 1]; (* Michael Somos, Jun 07 2021 *)
PROG
(PARI) { for (n=1, 11, if (n==1, a=3, a=a^2 + 1); write("b062013.txt", n, " ", a) ) } [Harry J. Smith, Jul 29 2009]
CROSSREFS
Sequence in context: A015487 A326428 A260813 * A023372 A025541 A203903
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jun 01 2001
EXTENSIONS
More terms from Jason Earls, Jun 02 2001
Offset changed from 0,1 to 1,1 by Harry J. Smith, Jul 29 2009
Typo in a(8) corrected by N. J. A. Sloane, Aug 31 2009 using the b-file.
STATUS
approved