%I A000199 M2285 N0904
%S A000199 1,3,3,7,6,12,13,20,21,34,36,51,58,78,89,118,131,171,197,245,279,349,
%T A000199 398,486,557,671,767,920,1046,1244,1421,1667,1898,2225,2525,2937,3333,
%U A000199 3856,4367,5034,5683,6521,7365,8409,9473,10795,12133,13775,15466
%N A000199 Coefficient of q^(2n-1) in the series expansion of Ramanujan's mock theta 
               function f(q).
%D A000199 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000199 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000199 L. A. Dragonette, Some Asymptotic Formulae for the Mock Theta Series 
               of Ramanujan, Trans. Amer. Math. Soc., 72 (1952), 474-500.
%H A000199 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               MockThetaFunction.html">Link to a section of The World of Mathematics.</
               a>
%t A000199 f[q_, s_] := Sum[q^(n^2)/Product[1+q^k, {k, n}]^2, {n, 0, s}]; Take[CoefficientList[Series[f[q, 
               100 ], {q, 0, 100}], q], {2, -1, 2}]
%o A000199 (PARI) a(n)=if(n<1,0,polcoeff(1+sum(k=1,sqrtint(2*n-1),x^k^2/prod(i=1,
               k,1+x^i,1+O(x^(2*n-1)))^2),2*n-1))
%Y A000199 A000025(2n-1)=a(n). Cf. A000039.
%Y A000199 Sequence in context: A078708 A096273 A069981 this_sequence A161771 A160515 
               A105670
%Y A000199 Adjacent sequences: A000196 A000197 A000198 this_sequence A000200 A000201 
               A000202
%K A000199 nonn
%O A000199 1,2
%A A000199 N. J. A. Sloane (njas(AT)research.att.com).
%E A000199 More terms from Eric Weisstein (eric(AT)weisstein.com)