G.f.: exp( Sum_{n>=1} A203414(n)*x^n/n ) where A203414(n) = n*Pell(n)*Sum_{d|n} 1/(d*Pell(d)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =25a(5) =64a(6) =200a(7) =512a(8) =1528a(9) =4048a(10) =11654a(11) =30585a(12) =88601a(13) =231295a(14) =651713a(15) =1733011a(16) =4814031a(17) =12685230a(18) =35225415a(19) =92628772a(20) =254268558a(21) =672643614a(22) =1826716115a(23) =4814931851a(24) =13086575526a(25) =34391797265a(26) =92637759753a(27) =244294085952a(28) =654813738224