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%I #10 May 12 2019 02:20:39
%S 1,4,28,364,9100,445900,43252300
%N Numbers appearing the third column of A155103.
%p A155102 := proc(n,k) if n = k then 1 ; elif n =2*k then -k-1 ; else 0; end if; end proc:
%p A155103 := proc(amx) a := array(1..amx,1..amx) ; a[1,1] := 1/A155102(1,1) ;
%p for r from 1 to amx do
%p for c from 1 to r-1 do a[c,r] := 0 ; end do:
%p a[r,r] := 1/A155102(r,r) ;
%p for c from r-1 to 1 by -1 do a[r,c] := -add(a[cp,c]*A155102(r,cp),cp=c..r-1)/A155102(r,r) ;
%p if c = 3 and a[r,c] <> 0 then print( a[r,c]) ; end if;
%p end do:
%p end do:
%p return ;
%p end proc:
%p A155103(290) ; # _R. J. Mathar_, Dec 07 2010
%K nonn,more
%O 1,2
%A _Mats Granvik_, Jan 20 2009
%E Two more terms from _R. J. Mathar_, Dec 07 2010
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