Triangle read by rows: T(0,0) = 1; T(n,k) = T(n-1,k) + 9 * T(n-2,k-1) for k = 0..floor(n/2); T(n,k)=0 for n or k < 0.
A317051
Triangle read by rows: T(0,0) = 1; T(n,k) = T(n-1,k) + 9 * T(n-2,k-1) for k = 0..floor(n/2); T(n,k)=0 for n or k < 0.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =9a(4) =1a(5) =18a(6) =1a(7) =27a(8) =81a(9) =1a(10) =36a(11) =243a(12) =1a(13) =45a(14) =486a(15) =729a(16) =1a(17) =54a(18) =810a(19) =2916a(20) =1a(21) =63a(22) =1215a(23) =7290a(24) =6561a(25) =1a(26) =72a(27) =1701a(28) =14580a(29) =32805
External references
- oeis: A317051