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A086170
a(1)=1; a(n)=a(n-1)+1 if n is in the sequence; a(n)=a(n-1)+2 if n and (n-1) are not in the sequence; a(n)=a(n-1)+3 if n is not in the sequence but (n-1) is in the sequence.
0
1, 4, 6, 7, 10, 11, 12, 15, 17, 18, 19, 20, 23, 25, 26, 29, 30, 31, 32, 33, 36, 38, 39, 42, 43, 44, 47, 49, 50, 51, 52, 53, 54, 57, 59, 60, 63, 64, 65, 68, 70, 71, 72, 73, 76, 78, 79, 82, 83, 84, 85, 86, 87, 88, 91, 93, 94, 97, 98, 99, 102, 104, 105, 106, 107, 110, 112, 113
OFFSET
1,2
FORMULA
a(n)=phi*n +O(1) where phi=(1+sqrt(5))/2
CROSSREFS
Sequence in context: A340833 A340847 A286494 * A123088 A256657 A189085
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Sep 13 2003
EXTENSIONS
Corrected by T. D. Noe, Oct 25 2006
STATUS
approved