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Triangle read by rows: Matrix inverse of A155102.
5

%I #5 Jul 19 2012 05:38:56

%S 1,2,1,0,0,1,6,3,0,1,0,0,0,0,1,0,0,4,0,0,1,0,0,0,0,0,0,1,30,15,0,5,0,

%T 0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,6,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,

%U 0,28,0,0,7,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,8,0,0,0,0,0,0

%N Triangle read by rows: Matrix inverse of A155102.

%C A028361 appears in the first column at A036987 positions. A028362 appears in the second column, A155105 in the third and A155104 in the fourth. A000384 appears as the third ray from zero and A100147 as the fourth.

%e Table begins:

%e 1,

%e 2,1,

%e 0,0,1,

%e 6,3,0,1,

%e 0,0,0,0,1,

%e 0,0,4,0,0,1,

%e 0,0,0,0,0,0,1,

%e 30,15,0,5,0,0,0,1,

%t m = 14; t = Inverse[ Table[ Which[n == k, 1, n == 2*k, -k - 1, True, 0], {n, 1, m}, {k, 1, m}]]; Flatten[ Table[t[[n, k]], {n, 1, m}, {k, 1, n}]] (* _Jean-François Alcover_, Jul 19 2012 *)

%Y Cf. A028361, A036987, A028362, A155105, A155104. A000384, A100147.

%K nonn,tabl

%O 1,2

%A _Mats Granvik_, Jan 20 2009