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 A075876 Values of n for which A075825(n)=1. 0
 0, 2, 4, 12, 52, 212, 852, 3412, 13652, 54612, 218452, 873812, 3495252, 13981012 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS For n > 4 it appears that a(n) = 4a(n-1) + 4. From Robert Israel, Nov 08 2016: (Start) By induction, we have for k >= 0:   A075825((10*4^k-7)/3) = 2^(k+1)   A075825((10*4^k-4)/3) = 1   A075825((10*4^k-1)/3) = 2^(k+1)+1   A075825((20*4^k-8)/3) = 2^(k+1)-1   A075825((20*4^k-5)/3) = 2^(k+1)+1   A075825((20*4^k-1)/3) = 2^(k+1) In particular, this sequence contains b(k) = (10*4^k-4)/3 which is the solution of b(k) = 4*b(k-1)+4 with b(0) = 2. The only terms <= 2*10^7 that are not of that form are 0 and 4. (End) LINKS CROSSREFS Cf. A075825. Sequence in context: A030924 A030831 A058767 * A222470 A227037 A158569 Adjacent sequences:  A075873 A075874 A075875 * A075877 A075878 A075879 KEYWORD nonn AUTHOR John W. Layman, Oct 16 2002 EXTENSIONS a(10)-a(14) from Robert Israel, Nov 08 2016 STATUS approved

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Last modified September 28 17:43 EDT 2020. Contains 337393 sequences. (Running on oeis4.)