Numbers k that divide s(k), where s(1)=1, s(j)=3*s(j-1)+j.

Terms

a(0) =1a(1) =3a(2) =39a(3) =507a(4) =6591a(5) =12207a(6) =85683a(7) =158691a(8) =255567a(9) =285987a(10) =1028703a(11) =1113879a(12) =2062983a(13) =3322371a(14) =3717831a(15) =3820791a(16) =13373139a(17) =14480427a(18) =26818779a(19) =31089279a(20) =43190823a(21) =48331803a(22) =49670283a(23) =79992471a(24) =89513931a(25) =173850807a(26) =188245551a(27) =321984039a(28) =348644127a(29) =404160627