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Number of partitions of n with no even parts repeated and with no 1's.
1

%I #6 Mar 07 2016 04:57:36

%S 1,0,1,1,1,2,3,3,4,6,7,9,12,14,18,23,27,34,42,50,62,75,89,108,130,154,

%T 184,220,259,307,364,426,502,590,688,806,941,1093,1272,1478,1710,1980,

%U 2290,2638,3042,3503,4021,4618,5296,6060,6934,7924,9038,10306,11740

%N Number of partitions of n with no even parts repeated and with no 1's.

%C Column 0 of A117274.

%F G.f.: (1+x^2)*product((1+x^(2k))/(1-x^(2k-1)), k=2..infinity).

%F a(n) ~ exp(sqrt(n/2)*Pi) * Pi / (2^(17/4) * n^(5/4)). - _Vaclav Kotesovec_, Mar 07 2016

%e a(8)=4 because we have [8],[6,2],[5,3] and [3,3,2].

%p g:=(1+x^2)*product((1+x^(2*k))/(1-x^(2*k-1)),k=2..53): gser:=series(g,x=0,62): seq(coeff(gser,x,n),n=0..58);

%t nmax = 60; CoefficientList[Series[(1-x) * Product[(1+x^(2*k))/(1-x^(2*k-1)), {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Mar 07 2016 *)

%Y Cf. A117274.

%K nonn

%O 0,6

%A _Emeric Deutsch_, Mar 06 2006