Positions of sevens (ground states) in A084451.

Terms

a(0) =0a(1) =4a(2) =9a(3) =35a(4) =42a(5) =101a(6) =143a(7) =365a(8) =693a(9) =729a(10) =926a(11) =1691a(12) =1721a(13) =2264a(14) =2858a(15) =3671a(16) =4919a(17) =7851a(18) =8469a(19) =8988a(20) =11401a(21) =12087a(22) =15246a(23) =21265a(24) =21410a(25) =28542a(26) =30539a(27) =35126a(28) =40991a(29) =49589