login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A191361
Number of the diagonal of the Wythoff difference array that contains n.
3
0, 1, -1, -2, 2, -3, 0, -4, -5, -1, -6, -7, 3, -8, -2, -9, -10, 1, -11, -3, -12, -13, -4, -14, -15, 0, -16, -5, -17, -18, -6, -19, -20, 4, -21, -7, -22, -23, -1, -24, -8, -25, -26, -9, -27, -28, 2, -29, -10, -30, -31, -2, -32, -11, -33, -34, -12, -35, -36, -3
OFFSET
1,4
COMMENTS
Every integer occurs in A191361 (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.
EXAMPLE
Diagonal #0 (the main diagonal) of A080164 is (1,7,26,...), so a(1)=0, a(7)=0, a(26)=0.
MATHEMATICA
r = GoldenRatio; f[n_] := Fibonacci[n];
g[i_, j_] := f[2 j - 1]*Floor[i*r] + (i - 1) f[2 j - 2];
TableForm[Table[g[i, j], {i, 1, 10}, {j, 1, 5}]]
(* A080164, Wythoff difference array *)
a = Flatten[Table[If[g[i, j] == n, j - i, {}], {n, 60}, {i, 50}, {j, 50}]]
(* a=A191361 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Clark Kimberling, May 31 2011
STATUS
approved