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 A229220 a(n) = a(n-1)^2 + (-1)^n with a(1)=1. 0
 1, 2, 3, 10, 99, 9802, 96079203, 9231213249115210, 85215298050640192157847853344099, 7261647021859442133580964784539140878185975659356185857298121802 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS From the 4th element, the sum of the digits (modulo 9) of each term gives the sequence A000035. LINKS Table of n, a(n) for n=1..10. FORMULA a(n) ~ c^(2^n), where c = 1.15442119601942274770665172928641533277.... - Vaclav Kotesovec, Oct 09 2013 MAPLE a := proc (n) if n = 1 then 1 else a(n-1)^2+(-1)^n end if end proc: seq(a(i), i = 1 .. 10); MATHEMATICA RecurrenceTable[{a[n] == a[n-1]^2 + (-1)^n, a[1]==1}, a, {n, 1, 10}] (* Vaclav Kotesovec, Oct 09 2013 *) PROG (PARI) a(n)=if(n==1, 1, a(n-1)^2+(-1)^n) \\ Charles R Greathouse IV, Sep 16 2013 CROSSREFS Cf. A000035. Sequence in context: A184249 A270356 A333332 * A155148 A076927 A064647 Adjacent sequences: A229217 A229218 A229219 * A229221 A229222 A229223 KEYWORD nonn AUTHOR Luca Finazzi, Sep 16 2013 STATUS approved

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Last modified September 7 08:00 EDT 2024. Contains 375729 sequences. (Running on oeis4.)