A051601 Rows of triangle formed using Pascal's rule except we begin and end the n-th row with n.
0, 1, 1, 2, 2, 2, 3, 4, 4, 3, 4, 7, 8, 7, 4, 5, 11, 15, 15, 11, 5, 6, 16, 26, 30, 26, 16, 6, 7, 22, 42, 56, 56, 42, 22, 7, 8, 29, 64, 98, 112, 98, 64, 29, 8, 9, 37, 93, 162, 210, 210, 162, 93, 37, 9, 10, 46, 130, 255, 372, 420, 372, 255, 130, 46, 10
Offset: 0
Examples
From _Roger L. Bagula_, Feb 17 2009: (Start) Triangle begins: 0; 1, 1; 2, 2, 2; 3, 4, 4, 3; 4, 7, 8, 7, 4; 5, 11, 15, 15, 11, 5; 6, 16, 26, 30, 26, 16, 6; 7, 22, 42, 56, 56, 42, 22, 7; 8, 29, 64, 98, 112, 98, 64, 29, 8; 9, 37, 93, 162, 210, 210, 162, 93, 37, 9; 10, 46, 130, 255, 372, 420, 372, 255, 130, 46, 10; 11, 56, 176, 385, 627, 792, 792, 627, 385, 176, 56, 11; 12, 67, 232, 561, 1012, 1419, 1584, 1419, 1012, 561, 232, 67, 12. ... (End)
Links
- Reinhard Zumkeller, Rows n = 0..120 of triangle, flattened
- B. E. Tenner, Spotlight tiling, Ann. Combinat. 14 (4) (2010) 553-568.
- Index entries for triangles and arrays related to Pascal's triangle
Crossrefs
Programs
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GAP
Flat(List([0..12], n-> List([0..n], k-> Binomial(n, k+1) + Binomial(n, n-k+1) ))); # G. C. Greubel, Nov 12 2019
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Haskell
a051601 n k = a051601_tabl !! n !! k a051601_row n = a051601_tabl !! n a051601_tabl = iterate (\row -> zipWith (+) ([1] ++ row) (row ++ [1])) [0] -- Reinhard Zumkeller, Nov 23 2012
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Magma
/* As triangle: */ [[Binomial(n,m+1)+Binomial(n,n-m+1): m in [0..n]]: n in [0..12]]; // Bruno Berselli, Aug 02 2013
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Maple
seq(seq(binomial(n,k+1) + binomial(n, n-k+1), k=0..n), n=0..12); # G. C. Greubel, Nov 12 2019
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Mathematica
T[n_, k_]:= T[n, k] = Binomial[n, k+1] + Binomial[n, n-k+1]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* Roger L. Bagula, Feb 17 2009; modified by G. C. Greubel, Nov 12 2019 *)
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PARI
T(n,k) = binomial(n, k+1) + binomial(n, n-k+1); for(n=0,12, for(k=0,n, print1(T(n,k), ", "))) \\ G. C. Greubel, Nov 12 2019
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Sage
[[binomial(n, k+1) + binomial(n, n-k+1) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 12 2019
Formula
T(m,n) = binomial(m+n,m) - 2*binomial(m+n-2,m-1), up to offset and transformation of array to triangular indices. - Bridget Tenner, Nov 10 2007
T(n,k) = binomial(n, k+1) + binomial(n, n-k+1). - Roger L. Bagula, Feb 17 2009
T(0,n) = T(n,0) = n, T(n,k) = T(n-1,k) + T(n-1,k-1), 0 < k < n.
Comments