a(1) = 1; a(n) = max{ 5*a(k) + a(n-k) | 1 <= k <= n/2 } for n > 1.

Terms

a(0) =1a(1) =6a(2) =11a(3) =36a(4) =41a(5) =66a(6) =91a(7) =216a(8) =221a(9) =246a(10) =271a(11) =396a(12) =421a(13) =546a(14) =671a(15) =1296a(16) =1301a(17) =1326a(18) =1351a(19) =1476a(20) =1501a(21) =1626a(22) =1751a(23) =2376a(24) =2401a(25) =2526a(26) =2651a(27) =3276a(28) =3401a(29) =4026