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Column 3 of triangle A132690.
4

%I #2 Mar 30 2012 18:37:04

%S 1,1,-4,35,-455,7735,-161336,3973212,-112587210,3603324835,

%T -128433778935,5042279130343,-216113991649920,10038333251577820,

%U -502213976534135280,26920671954736535620,-1539171664433009622090,93492751831594011076131,-6012423991038631627857900

%N Column 3 of triangle A132690.

%C Triangle T=A132690 is generated from negative powers of itself such that row n+1 of T = row n of T^(-n) with appended '1' for n>=0 with T(0,0)=1.

%o (PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+4, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^(-(i-2)))[i-1, j]); )); A=B); return( ((A)[n+4,4]))}

%Y Cf. A132690; A132691, A132692, A132693.

%K sign

%O 0,3

%A _Paul D. Hanna_, Aug 25 2007