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 A064657 a(n)=a(|n-a(n-3)|)+a(|n-a(n-4)|) for n>3, a(n)=1 otherwise. 3
 1, 1, 1, 1, 2, 4, 8, 12, 10, 5, 2, 2, 13, 12, 26, 13, 3, 9, 14, 11, 11, 25, 12, 26, 13, 13, 27, 27, 26, 4, 2, 6, 34, 10, 60, 5, 28, 53, 22, 62, 25, 24, 22, 25, 22, 51, 38, 25, 28, 3, 26, 53, 16, 53, 27, 63, 26, 4, 10, 12, 86, 57, 42, 79, 24, 36, 25, 38, 56, 32, 85, 23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS The sequence is defined only for n <= 866, see example. - Reinhard Zumkeller, Jul 21 2012 Sequence A064552 is defined in terms of this one. It is not immediate to see whether the sequence really is undefined or rather only implicitely defined for n>866. [It seems a priori conceivable to me that the given relation might be satisfied for a unique choice of all a(n).] - M. F. Hasler, Aug 28 2012 LINKS Reinhard Zumkeller, full Table of n, a(n) for n = 0..866 EXAMPLE Last term: a(866) = a(|866 - a(866-3)|) + a(|866 - a(866-4)|) = a(|866 - a(863)|) + a(|866 - a(862)|) = a(|866 - 718|) + a(|866 - 88|) = a(148) + a(778) = 28 + 655 = 683, but a(867) = a(|867 - a(867-3)|) + a(|867 - a(867-4)|) = a(|867 - a(864)|) + a(|867 - a(863)|) =  a(|867 - 2546|) + a(|867 - 718|) = a(1679) + a(149) = undefined + 112 = undefined. PROG (Haskell) a064657 n = a064657_list !! n a064657_list = map fromJust \$ takeWhile (/= Nothing) zs where   z n = fromJust \$ zs !! n   zs = (map Just [1, 1, 1, 1]) ++ f 4 where      f x = y : f (x + 1) where        y | 2*x < max i3 i4 = Nothing          | otherwise       = Just \$ z (abs (x - i3)) + z (abs (x - i4))          where i3 = z (x - 3); i4 = z (x - 4) b064657 = bFile' "A064657" a064657_list 0 -- (0.03 secs, 3184228 bytes) -- Reinhard Zumkeller, Jul 21 2012 (PARI) A064657_vec=[1, 1, 1]; A064657(n)={n<4 & return(1); #A064657_vec

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Last modified July 9 22:46 EDT 2020. Contains 335570 sequences. (Running on oeis4.)