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Pascal's triangle, right and left halves interchanged.
5

%I #15 Dec 25 2015 12:14:44

%S 1,1,1,1,1,2,3,1,1,3,4,1,1,4,6,10,5,1,1,5,10,15,6,1,1,6,15,20,35,21,7,

%T 1,1,7,21,35,56,28,8,1,1,8,28,56,70,126,84,36,9,1,1,9,36,84,126,210,

%U 120,45,10,1,1,10,45,120,210,252,462,330,165,55,11,1,1,11,55,165,330,462

%N Pascal's triangle, right and left halves interchanged.

%C Concatenations of rows of A014413 and A034868;

%C T(n,k) = if k <= [(n+1)/2] then A014413(n,k+1) else A034868(n,k-[(n+1)/2]);

%C alternative mirrored variant: concatenation of A034869 and A014462;

%C T(n,0) = A037952(n) for n > 0;

%C T(n,n) = A001405(n).

%H Reinhard Zumkeller, <a href="/A265848/b265848.txt">Rows n = 0..150 of triangle, flattened</a>

%H <a href="/index/Pas#Pascal">Index entries for triangles and arrays related to Pascal's triangle</a>

%F T(n,k) = A007318(n, (k + floor((n+2)/2)) mod (n+1)).

%e . 0: 1

%e . 1: 1 1

%e . 2: 1 1 2

%e . 3: 3 1 1 3

%e . 4: 4 1 1 4 6

%e . 5: 10 5 1 1 5 10

%e . 6: 15 6 1 1 6 15 20

%e . 7: 35 21 7 1 1 7 21 35

%e . 8: 56 28 8 1 1 8 28 56 70

%e . 9: 126 84 36 9 1 1 9 36 84 126

%e . 10: 210 120 45 10 1 1 10 45 120 210 252

%e . 11: 462 330 165 55 11 1 1 11 55 165 330 462

%e . 12: 792 495 220 66 12 1 1 12 66 220 495 792 924 .

%o (Haskell)

%o a265848 n k = a265848_tabl !! n !! k

%o a265848_row n = a265848_tabl !! n

%o a265848_tabl = zipWith (++) ([] : a014413_tabf) a034868_tabf

%Y Cf. A014413, A014462, A034868, A034869, A007318, A001405, A037952, A000079 (row sums), A001142 (row products).

%K nonn,tabl

%O 0,6

%A _Reinhard Zumkeller_, Dec 24 2015