a(n) = A027082(n, n+4).

Terms

a(0) =11a(1) =41a(2) =108a(3) =246a(4) =517a(5) =1035a(6) =2010a(7) =3828a(8) =7199a(9) =13429a(10) =24920a(11) =46090a(12) =85065a(13) =156791a(14) =288758a(15) =531528a(16) =978099a(17) =1799521a(18) =3310404a(19) =6089406a(20) =11200845a(21) =20602307a(22) =37894354a(23) =69699452a(24) =128198215a(25) =235794285a(26) =433694384a(27) =797689490a(28) =1467180945a(29) =2698567791