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A191988
Ordered sums 2f+5g, where f and g are Lucas numbers (A000032 beginning at 1).
5
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
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
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 20 2011
STATUS
approved