A155105 Numbers appearing the third column of A155103.

1, 4, 28, 364, 9100, 445900, 43252300

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Maple

A155102 := proc(n, k) if n = k then 1 ; elif n =2*k then -k-1 ; else 0; end if; end proc:
A155103 := proc(amx) a := array(1..amx, 1..amx) ; a[1, 1] := 1/A155102(1, 1) ;
        for r from 1 to amx do
                for c from 1 to r-1 do a[c, r] := 0 ; end do:
                a[r, r] := 1/A155102(r, r) ;
                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) ;
                        if c = 3 and a[r, c] <> 0 then print( a[r, c]) ; end if;
                end do:
        end do:
        return ;
end proc:
A155103(290) ; # R. J. Mathar, Dec 07 2010

Crossrefs

Sequence in context: A217903 A339283 A095288 * A132685 A180966 A203032

Adjacent sequences: A155102 A155103 A155104 * A155106 A155107 A155108

Keyword

nonn,more

Author

Mats Granvik, Jan 20 2009

Extensions

Two more terms from R. J. Mathar, Dec 07 2010

Status

approved