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A099257
a(1)=1, a(n+1) = if a(n)=n then 2*n+1 else smallest number not occurring earlier.
3
1, 3, 2, 4, 9, 5, 6, 7, 8, 10, 21, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 45, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 93, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
OFFSET
1,2
COMMENTS
Permutation of the natural numbers with inverse A099258;
a(A033484(n)) = A033484(n);
a(A033484(n) + 1) = 2*A033484(n) + 1 = A068156(n).
FORMULA
a(n) = if n = 3*2^k - 2 then n else (if n = 3*2^k - 1 then 2*n + 1 else n - 1).
CROSSREFS
Sequence in context: A300883 A019916 A201838 * A374789 A325909 A270701
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 09 2004
STATUS
approved