A191838 Ordered sums f+2*g, where f and g are positive Fibonacci numbers (A000045).

3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 21, 23, 24, 25, 27, 28, 29, 31, 34, 36, 37, 38, 39, 40, 43, 44, 45, 47, 50, 55, 57, 59, 60, 61, 63, 65, 69, 70, 71, 73, 76, 81, 89, 91, 93, 95, 97, 99, 102, 105, 111, 112, 113, 115, 118, 123, 131, 144

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Mathematica

c = 1; d = 2; f[n_] := Fibonacci[n];
g[n_] := c*f[n]; h[n_] := d*f[n];
t[i_, j_] := h[i] + g[j];
u = Table[t[i, j], {i, 1, 20}, {j, 1, 20}];
v = Union[Flatten[u ]]    (* A191838 *)
t1[i_, j_] := If[g[i] - h[j] > 0, g[i] - h[j], 0]
u1 = Table[t1[i, j], {i, 1, 20}, {j, 1, 20}];
v1 = Union[Flatten[u1 ]]  (* A191839: f(i)-2*f(j) *)
g1[n_] := d*f[n]; h1[n_] := c*f[n];
t2[i_, j_] := If[g1[i] - h1[j] > 0, g1[i] - h1[j], 0]
u2 = Table[t2[i, j], {i, 1, 20}, {j, 1, 20}];
v2 = Union[Flatten[u2 ]]  (* A191840: 2*f(i)-f(j) *)
v3 = Union[v1, v2]        (* A191841 *)
With[{nn=20}, Take[Union[#[[1]]+2#[[2]]&/@Tuples[Fibonacci[ Range[20]], 2]], 4nn]] (* Harvey P. Dale, Jun 08 2015 *)

Crossrefs

Cf. A191839, A191840, A191841.

Sequence in context: A192452 A132147 A118955 * A333214 A363768 A108473

Adjacent sequences: A191835 A191836 A191837 * A191839 A191840 A191841

Keyword

nonn

Author

Clark Kimberling, Jun 17 2011

Status

approved