The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A272908 Rectangular array, by antidiagonals: row n give the positions of n in the Lucas-products fractal sequence, A272907. 3

%I #5 May 14 2016 13:56:14

%S 1,2,5,3,7,8,4,10,11,16,6,13,14,20,23,9,17,18,25,28,35,12,21,22,30,33,

%T 41,46,15,26,27,36,39,48,53,62,19,31,32,42,45,55,60,70,77,24,37,38,49,

%U 52,63,68,79,86,97,29,43,44,56,59,71,76,88,95,107,116

%N Rectangular array, by antidiagonals: row n give the positions of n in the Lucas-products fractal sequence, A272907.

%C This array is an interspersion. Every positive integer occurs exactly once, and each row is interspersed by each other row, except for initial terms.

%e Northwest corner:

%e 1 2 3 4 6 9 12 15

%e 5 7 10 13 17 21 26 31

%e 8 11 14 18 22 27 32 38

%e 16 20 25 30 36 42 49 56

%e 23 28 33 39 45 52 59 67

%e 35 41 48 55 63 71 80 89

%e 46 53 60 68 76 85 94 104

%t z = 500; f[n_] := LucasL[n]; u1 = Table[f[n], {n, 1, z}];

%t u2 = Sort[Flatten[Table[f[i]*f[j], {i, 1, z}, {j, i, z}]]];

%t uf = Table[Select[Range[80], MemberQ[u1, u2[[i]]/f[#]] &][[1]], {i, 1, z}]

%t r[n_, k_] := Flatten[Position[uf, n]][[k]]

%t TableForm[Table[r[n, k], {n, 1, 12}, {k, 1, 12}]] (* A272908 array *)

%t Table[r[n - k + 1, k], {n, 12}, {k, n, 1, -1}] // Flatten (* A272908 sequence *)

%Y Cf. A000032, A272907, A272909, A272904 (Fibonacci-products interspersion).

%K nonn,tabl,easy

%O 1,2

%A _Clark Kimberling_, May 10 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 12 22:20 EDT 2024. Contains 375855 sequences. (Running on oeis4.)