This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A085143 #9 Jul 21 2023 07:48:48 %S A085143 1,-1,-1,-1,-1,-1,1,0,2,1,1,-2,4,3,1,-1,3,-11,-5,-5,-1,-1,-1,-34,10, %T A085143 -20,-8,-1,1,11,106,-116,96,44,13,1,1,15,368,-328,716,86,125,21,1,-1, %U A085143 13,-1324,-1344,-5634,1866,-1063,-316,-34,-1,-1,77,-4811,-17235 %N A085143 Triangle table from number wall of reversion of Fibonacci numbers. %F A085143 T(n, k) = det(f(i+j-1+k-n)_{i, j=1..n}) where f(n)=A007440(n). %F A085143 T(n, k) = (-1)^[(n+k-1)/2]*T(k-1, n-1) if 1<=k<=n. %e A085143 T(4,2)=0 since det([0,0,1,-1; 0,1,-1,0; 1,-1,0,2; -1,0,2,-3])=0. %e A085143 1 %e A085143 -1 -1 %e A085143 -1 -1 -1 %e A085143 1 0 2 1 %e A085143 1 -2 4 3 1 %e A085143 -1 3 -11 -5 -5 -1 %e A085143 -1 -1 -34 10 -20 -8 -1 %e A085143 1 11 106 -116 96 44 13 1 %e A085143 1 15 368 -328 716 86 125 21 1 %e A085143 -1 13 -1324 -1344 -5634 1866 -1063 -316 -34 -1 %p A085143 A085143 := proc(n,k) %p A085143 local A,r,c ; %p A085143 A := Matrix(n,n) ; %p A085143 for r from 1 to n do %p A085143 for c from 1 to n do %p A085143 A[r,c] := A007440(r+c-1+k-n) ; %p A085143 end do: %p A085143 end do: %p A085143 Determinant(A) ; %p A085143 end proc: %p A085143 seq(seq(A085143(n,k),k=1..n),n=1..12) ; # _R. J. Mathar_, Jul 21 2023 %o A085143 (PARI) {f(n)=polcoeff((-1-x+sqrt(1+2*x+5*x^2+x^2*O(x^n)))/(2*x),n)} \\ A007440 %o A085143 {T(n,k)=matdet(matrix(n,n,i,j,f(i+j-1+k-n)))} %Y A085143 Cf. A007440. %K A085143 sign,tabl %O A085143 1,9 %A A085143 _Michael Somos_, Jun 19 2003