G.f.: exp( Sum_{n>=1} A001333(n)^2 * x^n/n ) where A001333(n) = A002203(n)/2, one-half the companion Pell numbers.
A204061
G.f.: exp( Sum_{n>=1} A001333(n)^2 * x^n/n ) where A001333(n) = A002203(n)/2, one-half the companion Pell numbers.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =21a(4) =101a(5) =501a(6) =2561a(7) =13345a(8) =70561a(9) =377281a(10) =2035285a(11) =11059205a(12) =60454005a(13) =332138405a(14) =1832677185a(15) =10150115201a(16) =56398558081a(17) =314273655745
External references
- oeis: A204061