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A293052 Rectangular array by antidiagonals: T(n,m) = rank of n*sqrt(3)+m when all the numbers k*sqrt(3)+h, for k >= 1, h >= 0, are jointly ranked. 1

%I #6 Oct 06 2017 21:34:29

%S 1,2,3,4,5,7,6,8,10,13,9,11,14,17,20,12,15,18,22,25,29,16,19,23,27,31,

%T 35,40,21,24,28,33,37,42,47,53,26,30,34,39,44,49,55,61,67,32,36,41,46,

%U 51,57,63,70,76,83,38,43,48,54,59,65,72,79,86,93,101,45

%N Rectangular array by antidiagonals: T(n,m) = rank of n*sqrt(3)+m when all the numbers k*sqrt(3)+h, for k >= 1, h >= 0, are jointly ranked.

%C Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers. As an array, this is the interspersion of sqrt(1/3); see A283962.

%H Clark Kimberling, <a href="/A293052/b293052.txt">Antidiagonals n=1..60, flattened</a>

%F T(n,m) = Sum_{k=1...n + [m/r]} m+1+[(n-k)r], where r = sqrt(3), [ ]=floor.

%e Northwest corner:

%e 1 2 4 6 9 12 16

%e 3 5 8 11 15 19 24

%e 7 10 14 18 23 28 34

%e 13 17 22 27 33 39 46

%e 20 25 31 37 44 51 59

%e 29 35 42 49 57 65 74

%e 40 47 55 63 72 81 91

%e 53 61 70 79 89 99 110

%e 67 76 86 96 107 118 130

%e The numbers k*r+h, approximately:

%e (for k=1): 1.732 2.732 3.732 ...

%e (for k=2): 3.464 4.464 5.464 ...

%e (for k=3): 5.196 6.196 7.196 ...

%e Replacing each k*r+h by its rank gives

%e 1 2 4

%e 3 5 8

%e 7 10 14

%t r = Sqrt[3]; z = 12;

%t t[n_, m_] := Sum[Floor[1 + m + (n - k) r], {k, 1, n + Floor[m/r]}];

%t u = Table[t[n, m], {n, 1, z}, {m, 0, z}]

%t Grid[u] (* A293052 array *)

%t Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten (* A293052 sequence *)

%Y Cf. A283962.

%K nonn,easy,tabl

%O 1,2

%A _Clark Kimberling_, Oct 06 2017

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)