a(n) = 3*a(n-1) - a(n-2) with a(0)=1, a(1)=10.

Terms

a(0) =1a(1) =10a(2) =29a(3) =77a(4) =202a(5) =529a(6) =1385a(7) =3626a(8) =9493a(9) =24853a(10) =65066a(11) =170345a(12) =445969a(13) =1167562a(14) =3056717a(15) =8002589a(16) =20951050a(17) =54850561a(18) =143600633a(19) =375951338a(20) =984253381a(21) =2576808805a(22) =6746173034a(23) =17661710297a(24) =46238957857a(25) =121055163274