a(n) = 5*a(n-1) - 2*n for n > 0, a(0) = 1.

Terms

a(0) =1a(1) =3a(2) =11a(3) =49a(4) =237a(5) =1175a(6) =5863a(7) =29301a(8) =146489a(9) =732427a(10) =3662115a(11) =18310553a(12) =91552741a(13) =457763679a(14) =2288818367a(15) =11444091805a(16) =57220458993a(17) =286102294931