Half the number of n X n symmetric binary matrices with adjacent rows differing in at most one position.

A140176

Half the number of n X n symmetric binary matrices with adjacent rows differing in at most one position.

Terms

    a(0) =1a(1) =3a(2) =8a(3) =17a(4) =36a(5) =71a(6) =144a(7) =289a(8) =594a(9) =1231a(10) =2602a(11) =5573a(12) =12128a(13) =26727a(14) =59668a(15) =134729a(16) =307618a(17) =709503a(18) =1652402a(19) =3883445a(20) =9206712

External references