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A268584
a(0)=0; a(1)=0. For m>=1 : a(2*m) = 2*m-2-i, a(2*m+1) = 2*m-2-i, where i (0<=i<=n-2) is the smallest number such that a(2*m-2)-a(i)=0 AND a(2*m-1)-a(i+1)=0, or a(2*m)=0 AND a(2*m+1)=0 if no such i exists.
3
0, 0, 0, 0, 2, 2, 0, 0, 4, 4, 0, 0, 4, 4, 4, 4, 2, 2, 12, 12, 0, 0, 10, 10, 0, 0, 4, 4, 12, 12, 10, 10, 8, 8, 0, 0, 10, 10, 6, 6, 0, 0, 6, 6, 4, 4, 18, 18, 0, 0, 8, 8, 18, 18, 6, 6, 12, 12, 28, 28, 0, 0, 12, 12, 6, 6, 10, 10, 30, 30, 0, 0, 10, 10, 6, 6, 10, 10, 4, 4, 34, 34, 0, 0, 12, 12, 22, 22, 0, 0, 6, 6, 16, 16, 0, 0, 6, 6, 6, 6, 2, 2, 84, 84, 0, 0
OFFSET
0,5
COMMENTS
This sequence is a transformation of A181391. A181391(n)=(A268584(2*n-1)+A268584(2*n)) / 4.
EXAMPLE
a(0)=0 ; a(1)=0.
a(2)=0 ; a(3)=0. By definition, because no such i exists.
a(4)=(2-0)=2 ; a(5)=(3-1)=2.
a(6)=0 ; a(7)=0. By definition, because no such i exists.
a(8)=(6-2)=4 ; a(9)=(7-3)=4.
a(10)=0 ; a(11)=0. By definition, because no such i exists.
and so on.
CROSSREFS
KEYWORD
nonn
AUTHOR
Ctibor O. Zizka, Feb 07 2016
STATUS
approved