A191988 Ordered sums 2f+5g, where f and g are Lucas numbers (A000032 beginning at 1).

7, 11, 13, 17, 19, 21, 22, 23, 26, 27, 28, 29, 34, 37, 41, 42, 43, 49, 51, 56, 57, 61, 63, 69, 71, 73, 77, 78, 91, 92, 93, 96, 98, 99, 104, 109, 112, 113, 114, 126, 129, 147, 148, 149, 151, 153, 157, 159, 167, 172, 181, 184, 187, 203, 207, 237, 239, 241, 242

Offset

1,1

Links

Table of n, a(n) for n=1..59.

Mathematica

c = 2; 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]]    (* A191988 *)
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 191989: 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]]  (* A191990: d*f(i)-c*f(j) *)
v3 = Union[v1, v2]       (* A191991 *)

Crossrefs

Cf. A191989, A191990, A191991.

Sequence in context: A175811 A373140 A112588 * A128974 A286609 A005776

Adjacent sequences: A191985 A191986 A191987 * A191989 A191990 A191991

Keyword

nonn

Author

Clark Kimberling, Jun 20 2011

Status

approved