Numbers k such that k and k+1 are both terms in A377209.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =12a(6) =89a(7) =1824a(8) =3024a(9) =7024a(10) =15084a(11) =17184a(12) =18935a(13) =22624a(14) =28657a(15) =29424a(16) =31464a(17) =37024a(18) =38835a(19) =40032a(20) =42679a(21) =44975a(22) =47375a(23) =66744a(24) =66815a(25) =78219a(26) =89495a(27) =107456a(28) =112175a(29) =119744