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%I #9 Mar 19 2014 12:01:26
%S 1,3,4,7,7,9,13,12,13,16,21,19,19,21,25,31,28,27,28,31,36,43,39,37,37,
%T 39,43,49,57,52,49,48,49,52,57,64,73,67,63,61,61,63,67,73,81,91,84,79,
%U 76,75,76,79,84,91,100,111,103,97,93,91,91,93,97,103,111
%N Triangle read by rows: T(n,k) = n^2 - n*k + k^2, 1 <= k <= n.
%C T(n,k) = A093995(n,k) - A075362(n,k) + A133819(n,k) = 2*A070216(n,k) - A215631(n,k), 1 <= k <= n.
%H Reinhard Zumkeller, <a href="/A215630/b215630.txt">Rows n = 1..120 of triangle, flattened</a>
%e The triangle begins:
%e . 1: 1
%e . 2: 3 4
%e . 3: 7 7 9
%e . 4: 13 12 13 16
%e . 5: 21 19 19 21 25
%e . 6: 31 28 27 28 31 36
%e . 7: 43 39 37 37 39 43 49
%e . 8: 57 52 49 48 49 52 57 64
%e . 9: 73 67 63 61 61 63 67 73 81
%e . 10: 91 84 79 76 75 76 79 84 91 100
%e . 11: 111 103 97 93 91 91 93 97 103 111 121
%e . 12: 133 124 117 112 109 108 109 112 117 124 133 144 .
%o (Haskell)
%o a215630 n k = a215630_tabl !! (n-1) !! (k-1)
%o a215630_row n = a215630_tabl !! (n-1)
%o a215630_tabl = zipWith3 (zipWith3 (\u v w -> u - v + w))
%o a093995_tabl a075362_tabl a133819_tabl
%Y Cf. A004068 (row sums), A002061 (left edge), A000290 (right edge).
%Y Cf. A003215 (central terms).
%K nonn,tabl
%O 1,2
%A _Reinhard Zumkeller_, Nov 11 2012
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