A140182 Binomial transform of an infinite bidiagonal matrix with (1,3,1,3,1,3,...) in the main diagonal, (1,1,1,...) in the subdiagonal, the rest zeros.
1, 2, 3, 3, 7, 1, 4, 12, 4, 3, 5, 18, 10, 13, 1, 6, 25, 20, 35, 6, 3, 7, 33, 35, 75, 21, 19, 1, 8, 42, 56, 140, 56, 70, 8, 3, 9, 52, 84, 238, 126, 196, 36, 25, 1, 10, 63, 120, 378, 252, 462, 120, 117, 10, 3, 11, 75, 165, 570, 462, 966, 330, 405, 55, 31, 1
Offset: 0
Examples
First few rows of the triangle are: 1; 2, 3; 3, 7, 1; 4, 12, 4, 3; 5, 18, 10, 13, 1; 6, 25, 20, 35, 6, 3; 7, 33, 35, 75, 21, 19, 1; ...
Crossrefs
Cf. A052940.
Programs
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Maple
T:=proc(n,k) if `mod`(k,2)=0 then binomial(n+1,k+1) else 2*binomial(n,k)+binomial(n+1,k+1) end if end proc: for n from 0 to 10 do seq(T(n,k),k=0..n) end do; # yields sequence in triangular form - Emeric Deutsch, May 18 2008
Formula
A007318 as an infinite lower triangular matrix * a bidiagonal matrix with (1,3,1,3,1,3,...) in the main diagonal, (1,1,1,...) in the subdiagonal and the rest zeros.
From Emeric Deutsch, May 18 2008: (Start)
T(n, 2k) = binomial(n+1, 2k+1);
T(n, 2k+1) = 2*binomial(n, 2k+1) + binomial(n+1, 2k+2). (End)
Comments