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 A216191 Triangle T read by rows: T(n,k) equals the Manhattan distance between n and k when integers are arranged in a spiral. 0
 0, 1, 0, 2, 1, 0, 1, 2, 1, 0, 2, 3, 2, 1, 0, 1, 2, 3, 2, 1, 0, 2, 3, 4, 3, 2, 1, 0, 1, 2, 3, 2, 3, 2, 1, 0, 2, 1, 2, 3, 4, 3, 2, 1, 0, 3, 2, 3, 4, 5, 4, 3, 2, 1, 0, 2, 1, 2, 3, 4, 3, 4, 3, 2, 1, 0, 3, 2, 1, 2, 3 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Spiral begins (0 at the center): .   42--43--44--45--46--47--48    |   41  20--21--22--23--24--25    |   |                   |   40  19   6---7---8---9  26    |   |   |           |   |   39  18   5   0---1  10  27    |   |   |       |   |   |   38  17   4---3---2  11  28    |   |               |   |   37  16--15--14--13--12  29    |                       |   36--35--34--33--32--31--30 LINKS FORMULA T(n,n) = 0, T(n+1,n) = 1, T(n+2,n) = 2, T(n,k) <= n-k. EXAMPLE Triangle begins, 0 <= k <= n:   0   1, 0   2, 1, 0   1, 2, 1, 0   2, 3, 2, 1, 0   1, 2, 3, 2, 1, 0   2, 3, 4, 3, 2, 1, 0   1, 2, 3, 2, 3, 2, 1, 0   2, 1, 2, 3, 4, 3, 2, 1, 0   3, 2, 3, 4, 5, 4, 3, 2, 1, 0   2, 1, 2, 3, 4, 3, 4, 3, 2, 1, 0   3, 2, 1, 2, 3, 4, 5, 4, 3, 2, 1, 0   4, 3, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0   3, 2, 1, 2, 3, 4, 5, 4, 3, 4, 3, 2, 1, 0   2, 3, 2, 1, 2, 3, 4, 3, 4, 5, 4, 3, 2, 1, 0   3, 4, 3, 2, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0 CROSSREFS Sequence in context: A106262 A025870 A104276 * A268834 A285914 A096875 Adjacent sequences:  A216188 A216189 A216190 * A216192 A216193 A216194 KEYWORD nonn,tabl AUTHOR Philippe Deléham, Mar 11 2013 STATUS approved

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Last modified August 3 06:43 EDT 2021. Contains 346435 sequences. (Running on oeis4.)