A202874 Symmetric matrix based on (1,2,3,5,8,13,...), by antidiagonals.

1, 2, 2, 3, 5, 3, 5, 8, 8, 5, 8, 13, 14, 13, 8, 13, 21, 23, 23, 21, 13, 21, 34, 37, 39, 37, 34, 21, 34, 55, 60, 63, 63, 60, 55, 34, 55, 89, 97, 102, 103, 102, 97, 89, 55, 89, 144, 157, 165, 167, 167, 165, 157, 144, 89, 144, 233, 254, 267, 270, 272, 270, 267, 254

Offset: 1

Author

Clark Kimberling, Dec 26 2011

Keywords

• nonn
• tabl

Comments

Let s=(1,2,3,5,8,13,...)=(F(k+1)), where F=A000045, and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202874 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202875 for characteristic polynomials of principal submatrices of M, with interlacing zeros.

Examples

			Northwest corner:
1....2....3....5....8....13
2....5....8....13...21...34
3....8....14...23...37...60
5....13...23...39...63...102
8....21...37...63...102..167
		

Crossrefs

Cf. A202875.

Programs

Mathematica

s[k_] := Fibonacci[k + 1];
U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[s[k], {k, 1, 15}]];
L = Transpose[U]; M = L.U; TableForm[M]
m[i_, j_] := M[[i]][[j]];
Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]
f[n_] := Sum[m[i, n], {i, 1, n}] + Sum[m[n, j], {j, 1, n - 1}]
Table[f[n], {n, 1, 12}]
Table[Sqrt[f[n]], {n, 1, 12}]  (* A001911 *)
Table[m[1, j], {j, 1, 12}]     (* A000045 *)
Table[m[j, j], {j, 1, 12}]     (* A119996 *)
Table[m[j, j + 1], {j, 1, 12}] (* A180664 *)
Table[Sum[m[i, n + 1 - i], {i, 1, n}], {n, 1, 12}]  (* A002940 *)