a(n)=T(n,n-4), T given by A026568. Also a(n) = number of integer strings s(0),...,s(n) counted by T, such that s(n)=4.

A026573

a(n)=T(n,n-4), T given by A026568. Also a(n) = number of integer strings s(0),...,s(n) counted by T, such that s(n)=4.

Terms

    a(0) =1a(1) =3a(2) =12a(3) =34a(4) =103a(5) =281a(6) =778a(7) =2072a(8) =5524a(9) =14488a(10) =37918a(11) =98474a(12) =255137a(13) =658351a(14) =1695542a(15) =4356520a(16) =11177720a(17) =28637452a(18) =73294698a(19) =187412326a(20) =478861373a(21) =1222765699a(22) =3120722598a(23) =7961152560a(24) =20302100415a(25) =51757554237

External references