Coefficient of q^1 in nu(n), where nu(0)=1, nu(1)=b and, for n>=2, nu(n)=b*nu(n-1)+lambda*(1+q+q^2+...+q^(n-2))*nu(n-2) with (b,lambda)=(1,3).

A074355

Coefficient of q^1 in nu(n), where nu(0)=1, nu(1)=b and, for n>=2, nu(n)=b*nu(n-1)+lambda*(1+q+q^2+...+q^(n-2))*nu(n-2) with (b,lambda)=(1,3).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =3a(4) =15a(5) =45a(6) =147a(7) =402a(8) =1134a(9) =2991a(10) =7917a(11) =20367a(12) =52167a(13) =131748a(14) =330876a(15) =824187a(16) =2042763a(17) =5035473a(18) =12361755a(19) =30226614a(20) =73664298a(21) =178971879a(22) =433649769a(23) =1048133619a(24) =2527706127a(25) =6083434824a(26) =14613750648a(27) =35045236083a(28) =83909261319

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