%I A104624
%S A104624 1,2,2,0,2,0,4,0,10,0,28,0,84,0,264,0,858,0,2860,0,9724,0,33592,0,117572,
               0,
%T A104624 416024,0,1485800,0,5348880,0,19389690,0,70715340,0,259289580,0,955277400,
               0,
%U A104624 3534526380,0,13128240840,0,48932534040,0,182965127280,0,686119227300,
               0
%V A104624 1,-2,2,0,-2,0,4,0,-10,0,28,0,-84,0,264,0,-858,0,2860,0,-9724,0,33592,
               0,-117572,0,
%W A104624 416024,0,-1485800,0,5348880,0,-19389690,0,70715340,0,-259289580,0,955277400,
               0,
%X A104624 -3534526380,0,13128240840,0,-48932534040,0,182965127280,0,-686119227300,
               0
%N A104624 Reversion of binomial(2n,n) (A000984).
%C A104624 First column in inverse of A054335.
%F A104624 G.f.: sqrt(1+4x^2)-2x
%F A104624 The positive sequence 1,2,2,0,2,.... has g.f. 2(1+x)-sqrt(1-4x^2). - 
               Paul Barry (pbarry(AT)wit.ie), Oct 10 2007
%Y A104624 Sequence in context: A122157 A080378 A120439 this_sequence A049850 A050949 
               A074943
%Y A104624 Adjacent sequences: A104621 A104622 A104623 this_sequence A104625 A104626 
               A104627
%K A104624 easy,sign
%O A104624 0,2
%A A104624 Paul Barry (pbarry(AT)wit.ie), Mar 17 2005