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 A121414 Column 2 of triangle A121412, in which row n of T=A121412 equals row (n-1) of T^(n+1) with an appended '1'. 7

%I

%S 1,1,5,45,581,9730,199692,4843125,135345925,4278317373,150818840250,

%T 5863215069621,249105031449435,11480173020040450,570303168053225908,

%U 30375972794764190385,1726700205634807475115,104332294453480284687895

%N Column 2 of triangle A121412, in which row n of T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

%C Also equals column 4 of triangle A101479.

%o (PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+3, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^1)[n+3, 3])}

%Y Cf. A121412 (triangle); other columns: A101483, A121413, A121415; A101479 (triangle).

%K nonn

%O 0,3

%A _Paul D. Hanna_, Aug 22 2006

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Last modified April 1 18:40 EDT 2023. Contains 361695 sequences. (Running on oeis4.)