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Riordan array (1,2+4x).
0

%I #11 Jan 25 2020 01:39:56

%S 1,0,2,0,4,4,0,0,16,8,0,0,16,48,16,0,0,0,96,128,32,0,0,0,64,384,320,

%T 64,0,0,0,0,512,1280,768,128,0,0,0,0,256,2560,3840,1792,256,0,0,0,0,0,

%U 2560,10240,10752,4096,512,0,0,0,0,0,1024,15360,35840,28672,9216,1024,0,0,0

%N Riordan array (1,2+4x).

%C Row sums are A063727. Diagonal sums are A052907.

%C The Riordan array (1, s+tx) defines T(n,k) = binomial(k,n-k)*s^k*(t/s)^(n-k). The row sums satisfy a(n) = s*a(n-1) + t*a(n-2) and the diagonal sums satisfy a(n) = s*a(n-2) + t*a(n-3).

%F Number triangle T(n,k) = binomial(k, n-k)*2^n; columns have g.f. (2x+4x^2)^k.

%F T(n,k) = A113953(n,k)*2^k = A026729(n,k)*2^n. - _Philippe Deléham_, Dec 11 2008

%e Rows begin

%e {1},

%e {0, 2},

%e {0, 4, 4},

%e {0, 0, 16, 8},

%e {0, 0, 16, 48, 16}, ...

%Y Cf. A026729, A038210, A052907, A063727, A113953.

%K easy,nonn,tabl

%O 0,3

%A _Paul Barry_, Sep 25 2004