a(n) = ((1+4*sqrt(2))*(4+sqrt(2))^n + (1-4*sqrt(2))*(4-sqrt(2))^n)/2.

A164300

a(n) = ((1+4*sqrt(2))*(4+sqrt(2))^n + (1-4*sqrt(2))*(4-sqrt(2))^n)/2.

Terms

    a(0) =1a(1) =12a(2) =82a(3) =488a(4) =2756a(5) =15216a(6) =83144a(7) =452128a(8) =2453008a(9) =13294272a(10) =72012064a(11) =389976704a(12) =2111644736a(13) =11433484032a(14) =61904845952a(15) =335169991168

External references