cp's OEIS Frontend

A110956 a(n) = permanent of the n X n matrix M of zeros and ones defined as follows: if we concatenate the rows of M to form a vector v of length n^2, v_i = 0 if i is an entry from the sequence A045506 (inscribe 2 spheres of curvature 2 inside sphere of curvature -1, continue to inscribe spheres where possible; the sequence gives list of curvatures).

%I A110956 #4 Mar 30 2012 18:54:34
%S A110956 2,6,20,0,368,2016
%N A110956 a(n) = permanent of the n X n matrix M of zeros and ones defined as follows: if we concatenate the rows of M to form a vector v of length n^2, v_i = 0 if i is an entry from the sequence A045506 (inscribe 2 spheres of curvature 2 inside sphere of curvature -1, continue to inscribe spheres where possible; the sequence gives list of curvatures).
%Y A110956 Cf. A045506.
%K A110956 nonn
%O A110956 3,1
%A A110956 _Simone Severini_, Sep 26 2005