A191988 - OEIS

%I #5 Mar 30 2012 18:57:33

%S 7,11,13,17,19,21,22,23,26,27,28,29,34,37,41,42,43,49,51,56,57,61,63,

%T 69,71,73,77,78,91,92,93,96,98,99,104,109,112,113,114,126,129,147,148,

%U 149,151,153,157,159,167,172,181,184,187,203,207,237,239,241,242

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

%t c = 2; d = 5; f[n_] := LucasL[n];

%t g[n_] := c*f[n]; h[n_] := d*f[n];

%t t[i_, j_] := h[i] + g[j];

%t u = Table[t[i, j], {i, 1, 20}, {j, 1, 20}];

%t v = Union[Flatten[u]]    (* A191988 *)

%t t1[i_, j_] := If[g[i] - h[j] > 0, g[i] - h[j], 0]

%t u1 = Table[t1[i, j], {i, 1, 20}, {j, 1, 20}];

%t v1 = Union[Flatten[u1]]  (*A 191989: c*f(i)-d*f(j) *)

%t g1[n_] := d*f[n]; h1[n_] := c*f[n];

%t t2[i_, j_] := If[g1[i] - h1[j] > 0, g1[i] - h1[j], 0]

%t u2 = Table[t2[i, j], {i, 1, 20}, {j, 1, 20}];

%t v2 = Union[Flatten[u2]]  (* A191990: d*f(i)-c*f(j) *)

%t v3 = Union[v1, v2]       (* A191991 *)

%Y Cf. A191989, A191990, A191991.

%K nonn

%O 1,1

%A _Clark Kimberling_, Jun 20 2011