cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A004091 Fibonacci numbers written backwards.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 8, 31, 12, 43, 55, 98, 441, 332, 773, 16, 789, 7951, 4852, 1814, 5676, 64901, 11771, 75682, 86364, 52057, 393121, 814691, 118713, 922415, 40238, 9626431, 9038712, 8754253, 7882075, 5647229, 25303941, 71875142, 96188093, 68954236, 551433201, 141085561, 692419762, 734494334, 337804107, 713094311, 3091136381, 3705121792
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Comments

Or, Fibonacci numbers reversed.

Links

Crossrefs

Cf. A000045, A004170, A014258.

Programs

  • Haskell
    a004091 = a004086 . a000045  -- Reinhard Zumkeller, Mar 08 2013
  • Magma
    [Seqint(Reverse(Intseq(Fibonacci(n)))): n in [0..50]]; // Vincenzo Librandi, Jan 17 2016
  • Maple
    a:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(
         ""||((<<0|1>, <1|1>>^n)[1,2])):
seq(a(n), n=0..50);  # Alois P. Heinz, Apr 09 2015
  • Mathematica
    FromDigits[Reverse[IntegerDigits[#]]]&/@Fibonacci[Range[50]] (* Harvey P. Dale, Jun 10 2011 *)
IntegerReverse[Fibonacci[Range[0,50]]] (* Harvey P. Dale, Jun 21 2024 *)
  • PARI
    a(n) = fromdigits(Vecrev(digits(fibonacci(n)))); \\ Michel Marcus, Mar 25 2024

Formula

a(n) = A004086(A000045(n)). - Reinhard Zumkeller, Mar 08 2013

A140463 Reversals of Lucas numbers (sorted).

Original entry on oeis.org

1, 2, 3, 4, 7, 11, 67, 74, 81, 92, 125, 223, 321, 348, 991, 1753, 4631, 7022, 8775, 9439, 30693, 67442, 72151, 97046, 167761, 286301, 344172, 402934, 746017, 1589411, 6911887, 7480784, 8940681, 9430103, 12581045, 28258333, 30830478, 34025721
Offset: 1

Views

Author

Jonathan Vos Post, Jun 23 2008

Keywords

Crossrefs

This is to A000032 as A004170 is to A000045.

Programs

  • Mathematica
    IntegerReverse[LucasL[Range[0,40]]]//Sort (* Harvey P. Dale, Jun 05 2023 *)

Extensions

More terms from R. J. Mathar, Feb 19 2009

A215649 Reversals of tribonacci numbers (sorted).

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 18, 31, 42, 44, 405, 472, 729, 941, 5071, 6313, 8675, 9853, 21066, 31591, 90601, 447014, 514121, 674557, 713322, 770074, 4606468, 7359831, 7575552, 8089735, 19520951, 52494292, 69005989, 106799181, 474396516, 777547433, 2586342311, 3016782802
Offset: 0

Views

Author

Jonathan Vos Post, Mar 09 2013

Keywords

Comments

This is to A004170 as tribonacci numbers A000073 are to Fibonacci numbers A000045. Note that tribonacci(20) = 35890 is, upon reversal, 09853, then the leading 0 is truncated, making the 5-digit number into the 4-digit number 9853. Similarly, R(4700770) = 770074.

Examples

			A000073(n) for n = 7, 8, 9 = 13, 24, 44, 81. Reversed, those are 31, 42, 44, 18, and sorted that is 18, 31, 42, 44.

Links

Crossrefs

Cf. A000045, A000073, A004086, A004170, A004091, A140463, A214855, A004086.

Programs

  • Mathematica
    Sort[FromDigits[Reverse[IntegerDigits[#]]]&/@LinearRecurrence[{1,1,1},{0,0,1,1},40]] (* Harvey P. Dale, Nov 22 2015 *)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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