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 A271354 Products of two distinct Fibonacci numbers, both greater than 1. 10
 6, 10, 15, 16, 24, 26, 39, 40, 42, 63, 65, 68, 102, 104, 105, 110, 165, 168, 170, 178, 267, 272, 273, 275, 288, 432, 440, 442, 445, 466, 699, 712, 714, 715, 720, 754, 1131, 1152, 1155, 1157, 1165, 1220, 1830, 1864, 1869, 1870, 1872, 1885, 1974, 2961, 3016 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For n > 5, the numbers F(i)*F(j) satisfying F(n-1) <= F(i)*F(j) <= F(n) also satisfy F(n-1) < F(i)*F(j) < F(n).  They are the numbers for which i + j = n + 1, where 2 < i < j, so that the number of such F(i)*F(j) is floor(n/2) - 2.  The least is 3*F(n-3) and the greatest is 2*F(n-2). LINKS Clark Kimberling, Table of n, a(n) for n = 1..1000 Clark Kimberling, Orderings of products of Fibonacci numbers, Fibonacci Quarterly 42:1 (2004), pp. 28-35. FORMULA A004526(n) = number of numbers a(k) between F(n+3) and F(n+4), where F = A000045 (Fibonacci numbers). EXAMPLE 2*3 = 6, 2*5 = 10, 3*5 = 15, 2*8 = 16. MATHEMATICA z = 200; f[n_] := Fibonacci[n]; Take[Sort[Flatten[Table[f[m] f[n], {n, 3, z}, {m, 3, n - 1}]]], 100] PROG (PARI) list(lim)=my(v=List, F=vector(A130233(lim\2), k, fibonacci(k)), t); for(i=2, #F, for(j=1, i-1, t=F[i]*F[j]; if(t>lim, break); listput(v, t))); Set(v) \\ Charles R Greathouse IV, Oct 07 2016 CROSSREFS Cf. A000045, A004526, A094565, A271356 (difference sequence), subsequence of A049997. Sequence in context: A095678 A151972 A094564 * A315240 A315241 A166160 Adjacent sequences:  A271351 A271352 A271353 * A271355 A271356 A271357 KEYWORD nonn,easy AUTHOR Clark Kimberling, May 02 2016 STATUS approved

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Last modified July 14 16:21 EDT 2020. Contains 335729 sequences. (Running on oeis4.)