A191980 Ordered sums f+5g, where f and g are Lucas numbers (A000032 beginning at 1).

6, 8, 9, 12, 16, 18, 19, 21, 22, 23, 24, 26, 27, 31, 33, 34, 36, 38, 39, 42, 44, 46, 49, 52, 53, 56, 58, 59, 62, 64, 66, 67, 73, 81, 82, 84, 91, 93, 94, 96, 97, 101, 102, 108, 111, 119, 128, 131, 137, 138, 143, 146, 148, 149, 152, 156, 158, 163, 166, 174

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Mathematica

c = 1; d = 5; f[n_] := LucasL[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]]    (* A191980 *)
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]]  (*A 191981: c*f(i)-d*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]]  (* A191982: d*f(i)-c*f(j) *)
v3 = Union[v1, v2]       (* A191983 *)
With[{nn=20}, Select[Union[(#[[1]]+5#[[2]]&/@Tuples[LucasL[Range[nn]], 2])], #<=LucasL[nn]+5&]] (* Harvey P. Dale, Dec 07 2018 *)

Crossrefs

Cf. A191981, A191981, A191982, A191983.

Sequence in context: A337381 A305704 A043720 * A304412 A161982 A285275

Adjacent sequences: A191977 A191978 A191979 * A191981 A191982 A191983

Keyword

nonn

Author

Clark Kimberling, Jun 20 2011

Status

approved