A097750 - OEIS

%I #27 Jan 26 2021 08:31:50

%S 1,1,2,1,4,4,1,6,11,8,1,8,22,26,16,1,10,37,64,57,32,1,12,56,130,163,

%T 120,64,1,14,79,232,386,382,247,128,1,16,106,378,794,1024,848,502,256,

%U 1,18,137,576,1471,2380,2510,1816,1013,512,1,20,172,834,2517,4944,6476,5812,3797,2036,1024

%N Reversal of the binomial transform of the Whitney triangle A004070 (see A131250), triangle read by rows, T(n,k) for 0 <= k <= n.

%C Reversal of the Riordan array (1/(1-2x), x/(1-x)^2), see A131250. Row sums are A061667 and diagonal sums of A131250 are A045623. The n-th row elements correspond to the end elements of the 2n-th row of the Whitney triangle A004070. A131250 corresponds to the product of Pascal's triangle and the Whitney triangle.

%F T(n, k) = Sum_{i=0..n} binomial(n+k, i-k).

%F T(n, k) = T(n-1,k)+2*T(n-1,k-1)-T(n-2,k-2), T(0,0)=1, T(1,0)=1, T(1,1)=2, T(n,k)=0 if k<0 or if k>n. - _Philippe Deléham_, Jan 11 2014

%F T(n, k) = binomial(2*n-k, k)*hypergeom([1, 1, -k], [1, 1 - 2*k + 2*n], -1). - _Peter Luschny_, Oct 28 2018

%e Triangle begins:

%e 1;

%e 1, 2;

%e 1, 4, 4;

%e 1, 6, 11, 8;

%e 1, 8, 22, 26, 16;

%e 1, 10, 37, 64, 57, 32;

%e 1, 12, 56, 130, 163, 120, 64;

%e 1, 14, 79, 232, 386, 382, 247, 128;

%p T := (n,k) -> binomial(2*n-k, k)*hypergeom([1, 1, -k], [1, 1-2*k+2*n], -1):

%p for n from 0 to 8 do seq(simplify(T(n, k)), k=0..n) od; # _Peter Luschny_, Oct 28 2018

%t T[_, 0] = 1; T[n_, n_] := 2^n; T[n_, k_] /; 0 < k < n := T[n, k] = T[n - 1, k] + 2 T[n - 1, k - 1] - T[n - 2, k - 2]; T[_, _] = 0;

%t Table[T[n, k], {n, 0, 10}, {k, 0, n}] (* _Jean-François Alcover_, Jun 19 2019 *)

%Y Row sums are A061667.

%Y Cf. A004070, A097761, A131250.

%K easy,nonn,tabl

%O 0,3

%A _Paul Barry_, Aug 23 2004

%E Definition and comments corrected by _Philippe Deléham_, Jan 11 2014