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

A164603

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

Terms

    a(0) =1a(1) =18a(2) =76a(3) =376a(4) =1808a(5) =8736a(6) =42176a(7) =203648a(8) =983296a(9) =4747776a(10) =22924288a(11) =110688256a(12) =534450176a(13) =2580553728a(14) =12460015616a(15) =60162277376a(16) =290489171968

External references