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A184403
"Types" (parities of i and j) when all the numbers i+j*r are ranked, where r=sqrt(2), i>=0, j>=0.
7
4, 2, 3, 4, 1, 4, 2, 3, 2, 4, 3, 1, 4, 2, 1, 3, 4, 2, 4, 3, 1, 2, 4, 2, 3, 1, 3, 4, 2, 4, 1, 3, 1, 4, 2, 4, 2, 3, 1, 3, 2, 4, 2, 3, 4, 1, 3, 1, 4, 2, 4, 1, 2, 3, 1, 4, 3, 2, 4, 2, 3, 4, 1, 3, 2, 1, 4, 2, 3, 4, 1, 2, 3, 1, 4, 3, 2, 4, 1, 2, 3, 4, 1, 4, 3, 2, 1, 4, 2, 3, 4, 1, 2, 3, 2, 1
OFFSET
1,1
FORMULA
Let s(n)=i(n)+r*j(n) be the sequence obtained by arranging in increasing order all the numbers i+j*r, where
r=2^(1/2) and i>=0, j>=0. Then
a(n)=1 if i(n) is odd and j(n) is odd (n in A184399);
a(n)=2 if i(n) is odd and j(n) is even (n in A184400);
a(n)=3 if i(n) is even and j(n) is odd (n in A184401);
a(n)=4 if i(n) is even and j(n) is even (n in A184402).
EXAMPLE
(See the examples at A184399-A184402.)
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 12 2011
STATUS
approved