Weighted tribonacci (1,2,4), companion to A102001.

Terms

a(0) =1a(1) =7a(2) =13a(3) =31a(4) =85a(5) =199a(6) =493a(7) =1231a(8) =3013a(9) =7447a(10) =18397a(11) =45343a(12) =111925a(13) =276199a(14) =681421a(15) =1681519a(16) =4149157a(17) =10237879a(18) =25262269a(19) =62334655a(20) =153810709a(21) =379529095a(22) =936489133a(23) =2310790159a(24) =5701884805a(25) =14069421655a(26) =34716351901a(27) =85662734431a(28) =211373124853a(29) =521564001319