Minimum value unattainable as the sum of 4 attained values of a*b*c with a,b,c 0..n integers.

Terms

a(0) =5a(1) =23a(2) =77a(3) =174a(4) =347a(5) =595a(6) =975a(7) =1489a(8) =2101a(9) =2911a(10) =4104a(11) =5053a(12) =6776a(13) =8391a(14) =10324a(15) =12933a(16) =15643a(17) =18637a(18) =22200a(19) =25466a(20) =30206a(21) =34659a(22) =39768a(23) =44905a(24) =51828a(25) =58383a(26) =65422a(27) =73453a(28) =81960a(29) =89647