%I A008556
%S A008556 1,2,6,2,20,12,70,60,6,252,280,60,924,1260,420,20,3432,5544,2520,280,
%T A008556 12870,24024,13860,2520,70,48620,102960,72072,18480,1260,184756,437580,
%U A008556 360360,120120,13860,252,705432,1847560,1750320,720720,120120,5544
%N A008556 Triangle of coefficients of Legendre polynomials 2^n P_n (x).
%D A008556 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, 
               National Bureau of Standards Applied Math. Series 55, 1964 (and various 
               reprintings), p. 798.
%H A008556 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.nrbook.com/
               abramowitz_and_stegun/">Handbook of Mathematical Functions</a>, National 
               Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 
               [alternative scanned copy].
%p A008556 series(1/sqrt(1-2*x*z+z^2),z,20): for n to 19 do print(2^n*coeff(%,z,
               n)); od;
%Y A008556 Sequence in context: A122663 A100892 A126287 this_sequence A096485 A125032 
               A131980
%Y A008556 Adjacent sequences: A008553 A008554 A008555 this_sequence A008557 A008558 
               A008559
%K A008556 nonn,tabl
%O A008556 0,2
%A A008556 N. J. A. Sloane (njas(AT)research.att.com).