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 A178910 Binary XOR of divisors of n. 19
 1, 3, 2, 7, 4, 6, 6, 15, 11, 12, 10, 14, 12, 10, 8, 31, 16, 29, 18, 28, 16, 30, 22, 30, 29, 20, 16, 18, 28, 24, 30, 63, 40, 48, 32, 49, 36, 54, 40, 60, 40, 48, 42, 54, 44, 58, 46, 62, 55, 39, 32, 36, 52, 48, 56, 34, 40, 36, 58, 56, 60, 34, 38, 127, 72, 120, 66, 112, 80, 96, 70 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS If 2^k <= n < 2^(k+1), then also 2^k <= a(n) < 2^(k+1), since any proper divisor of n is < 2^k. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..8191 PROG (PARI) a(n)=local(ds, r); ds=divisors(n); for(k=1, #ds, r=bitxor(r, ds[k])); r (Haskell) import Data.Bits (xor) a178910 = foldl1 xor . a027750_row :: Integer -> Integer -- Reinhard Zumkeller, Nov 17 2012 CROSSREFS Cf. A000203, A178908, A178911, A003987. Cf. A027750, A072594; subsequences A028982 (odd), A028982 (even). Sequence in context: A341916 A344878 A344875 * A182651 A175055 A085168 Adjacent sequences:  A178907 A178908 A178909 * A178911 A178912 A178913 KEYWORD base,nonn,look AUTHOR Franklin T. Adams-Watters, Jun 22 2010 STATUS approved

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Last modified August 6 00:46 EDT 2021. Contains 346493 sequences. (Running on oeis4.)