A191360 Number of the diagonal of the Wythoff array that contains n.

0, 1, 2, -1, 3, -2, 0, 4, -3, -1, 1, -4, 5, -5, -2, 0, -6, 2, -7, -3, 6, -8, -4, -1, -9, 1, -10, -5, 3, -11, -6, -2, -12, 7, -13, -7, -3, -14, 0, -15, -8, 2, -16, -9, -4, -17, 4, -18, -10, -5, -19, -1, -20, -11, 8, -21, -12, -6, -22, -2, -23, -13, 1, -24, -14, -7, -25, 3, -26, -15, -8, -27, -3, -28, -16, 5, -29, -17, -9, -30

Offset

1,3

Comments

Every integer occurs in this sequence (infinitely many times).

Represent the array as {g(i,j): i>=1, j>=1}. Then for m>=0, (diagonal #m) is the sequence (g(i,i+m)), i>=1; for m<0, (diagonal #m) is the sequence (g(i+m,i)), i>=1.

Links

Table of n, a(n) for n=1..80.

Example

The main diagonal of the Wythoff array is (1,7,16,...); that's diagonal #0, so that a(1)=0, a(7)=0, a(16)=0.

Mathematica

f[n_]:=f[n]=Fibonacci[n];
g[i_, j_]:=f[j+1]*Floor[i*GoldenRatio]+(i-1) f[j];
t=Table[g[i, j], {i, 500}, {j, 100}];
Map[#[[2]]-#[[1]]&, Most[Reap[NestWhileList[#+1&, 1, Length[Sow[FirstPosition[t, #]]]>1&]][[2]][[1]]]]  (* Peter J. C. Moses, Feb 09 2023 *)

Crossrefs

Cf. A035513, A114327, A191361, A191362.

Sequence in context: A190451 A373891 A282743 * A144029 A347030 A166949

Adjacent sequences: A191357 A191358 A191359 * A191361 A191362 A191363

Keyword

sign

Author

Clark Kimberling, May 31 2011

Extensions

Mathematica program replaced by Clark Kimberling, Feb 10 2023.

Status

approved