T(n,n+4), T given by A027960.

Terms

a(0) =1a(1) =7a(2) =26a(3) =73a(4) =174a(5) =373a(6) =743a(7) =1404a(8) =2552a(9) =4506a(10) =7784a(11) =13226a(12) =22193a(13) =36889a(14) =60882a(15) =99947a(16) =163430a(17) =266455a(18) =433495a(19) =704150a(20) =1142496a(21) =1852212a(22) =3001056a(23) =4860468a(24) =7869649a(25) =12739243a(26) =20619098a(27) =33369709a(28) =54001422a(29) =87385081