G.f.: A(x) = exp( Sum_{n>=1} 3*A038500(n) * x^n/n ), where A038500 is the highest power of 3 dividing n.
A161809
G.f.: A(x) = exp( Sum_{n>=1} 3*A038500(n) * x^n/n ), where A038500 is the highest power of 3 dividing n.
Terms
- a(0) =1a(1) =3a(2) =6a(3) =12a(4) =21a(5) =33a(6) =51a(7) =75a(8) =105a(9) =147a(10) =201a(11) =267a(12) =354a(13) =462a(14) =591a(15) =753a(16) =948a(17) =1176a(18) =1455a(19) =1785a(20) =2166a(21) =2622a(22) =3153a(23) =3759a(24) =4470a(25) =5286a(26) =6207a(27) =7275a(28) =8490a(29) =9852
External references
- oeis: A161809