Sorted positions of first appearances in A367905.

Terms

a(0) =1a(1) =4a(2) =7a(3) =20a(4) =68a(5) =320a(6) =352a(7) =1088a(8) =3136a(9) =5184a(10) =13376a(11) =16704a(12) =17472a(13) =70720a(14) =82240a(15) =83008a(16) =90112a(17) =90176