G.f.: exp( Sum_{n>=1} A056789(n)*x^n/n ), where A056789(n) = Sum_{k=1..n} lcm(k,n)/gcd(k,n).

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =10a(5) =23a(6) =40a(7) =86a(8) =159a(9) =300a(10) =559a(11) =1037a(12) =1887a(13) =3400a(14) =6102a(15) =10763a(16) =19027a(17) =33138a(18) =57621a(19) =99160a(20) =169934a(21) =289432a(22) =490208a(23) =826169a(24) =1385272a(25) =2312155a(26) =3840729a(27) =6354981a(28) =10467872a(29) =17179510