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A267363
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a(0) = 0; a(odd n) = 2n+1; a(even n) = a(n/2 - a(n-1)).
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1
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0, 3, -9, 7, -9, 11, 27, 15, -21, 19, 99, 23, -33, 27, 63, 31, -45, 35, -117, 39, -57, 43, 99, 47, -69, 51, -873, 55, -81, 59, 135, 63, -93, 67, -225, 71, -105, 75, 171, 79, -117, 83, 423, 87, -129, 91, 207, 95, -141, 99, -333, 103, -153, 107, 243, 111, -165
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OFFSET
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0,2
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LINKS
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FORMULA
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a(0) = 0; a(odd n) = 2n+1; a(even n) = a(n/2 - a(n-1)).
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MATHEMATICA
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a[0] = 0; a[n_] := a[n] = If[OddQ@ n, 2 n + 1, a[n/2 - a[n - 1]]]; Table[a@ n, {n, 56}] (* Michael De Vlieger, Jan 13 2016 *)
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PROG
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(Sidef)
func a({.is_zero}) { 0 }
func a(n {.is_odd}) { 2*n + 1 }
func a(n) is cached { a(n/2 - a(n-1)) }
0.to(10).each { |i| say a(i) }
(PARI) a(n) = if (n==0, 0, if (n % 2, 2*n+1, a(n/2 - a(n-1)))); \\ Michel Marcus, Jan 13 2016
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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