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.

A246558 Product of the digits of the n-th Fibonacci number.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 8, 3, 2, 12, 25, 72, 16, 18, 147, 0, 504, 315, 320, 32, 1260, 0, 49, 3360, 3456, 0, 162, 1728, 168, 720, 0, 7776, 0, 33600, 0, 30240, 0, 15680, 0, 311040, 0, 0, 326592, 435456, 0, 0, 0, 0, 0, 0, 0, 0, 0, 102060, 3951360, 24883200, 1411200
Offset: 0

Views

Author

Indrani Das, Nov 12 2014

Keywords

Comments

a(n) > 0 iff n in A076564.
Probably, the last nonzero term is a(184). - Giovanni Resta, Jul 14 2015

Examples

			Fibonacci(7) = 13, thus a(7) = 1*3 = 3.
		

Crossrefs

Programs

  • Haskell
    a246558 = a007954 . a000045 -- Reinhard Zumkeller, Nov 17 2014
    
  • Magma
    [0] cat [&*Intseq(Fibonacci(n)): n in [1..100]]; // Vincenzo Librandi, Jan 04 2020
    
  • Mathematica
    Array[Times@@IntegerDigits@Fibonacci[#]&, 100, 0] (* Vincenzo Librandi, Jan 04 2020 *)
  • PARI
    a(n) = if (n, vecprod(digits(fibonacci(n))), 0); \\ Michel Marcus, Feb 11 2025

Formula

a(n) = A007954(A000045(n)). - Reinhard Zumkeller, Nov 17 2014

A261575 Table of Fibonacci numbers in base-60 representation: row n contains the sexagesimal digits of A000045(n) in reversed order.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 29, 1, 24, 2, 53, 3, 17, 6, 10, 10, 27, 16, 37, 26, 4, 43, 41, 9, 1, 45, 52, 1, 26, 2, 3, 11, 55, 4, 37, 57, 7, 48, 52, 12, 25, 50, 20, 13, 43, 33, 38, 33, 54, 51, 16, 28, 1, 29, 50, 22, 2, 20, 7, 51, 3, 49, 57, 13, 6
Offset: 0

Views

Author

Reinhard Zumkeller, Sep 09 2015

Keywords

Comments

A261585(n) = length of n-th row;
T(n,0) = A261606(n) = in base 60: last sexagesimal digit of A000045(n);
T(n,A261607(n)-1) = A261607(n) = in base 60: initial sexagesimal digit of A000045(n);
A000045(n) = sum(T(n,k)*60^k : k = 0..A261585(n)-1).

Examples

			A000045(42) = 20*60^4 + 40*60^3 + 20*60^2 + 38*60^1 + 16*60^0 = 267914296.
. ----------------------------------------------------------------------
.   n | T(n,*)       n | T(n,*)             n | T(n,*)
. ----+---------   ----+---------------   ----+-------------------------
.   0 | [0]         21 | [26,2,3]          42 | [16,38,20,40,20]
.   1 | [1]         22 | [11,55,4]         43 | [17,7,55,26,33]
.   2 | [1]         23 | [37,57,7]         44 | [33,45,15,7,54]
.   3 | [2]         24 | [48,52,12]        45 | [50,52,10,34,27,1]
.   4 | [3]         25 | [25,50,20]        46 | [23,38,26,41,21,2]
.   5 | [5]         26 | [13,43,33]        47 | [13,31,37,15,49,3]
.   6 | [8]         27 | [38,33,54]        48 | [36,9,4,57,10,6]
.   7 | [13]        28 | [51,16,28,1]      49 | [49,40,41,12,0,10]
.   8 | [21]        29 | [29,50,22,2]      50 | [25,50,45,9,11,16]
.   9 | [34]        30 | [20,7,51,3]       51 | [14,31,27,22,11,26]
.  10 | [55]        31 | [49,57,13,6]      52 | [39,21,13,32,22,42]
.  11 | [29,1]      32 | [9,5,5,10]        53 | [53,52,40,54,33,8,1]
.  12 | [24,2]      33 | [58,2,19,16]      54 | [32,14,54,26,56,50,1]
.  13 | [53,3]      34 | [7,8,24,26]       55 | [25,7,35,21,30,59,2]
.  14 | [17,6]      35 | [5,11,43,42]      56 | [57,21,29,48,26,50,4]
.  15 | [10,10]     36 | [12,19,7,9,1]     57 | [22,29,4,10,57,49,7]
.  16 | [27,16]     37 | [17,30,50,51,1]   58 | [19,51,33,58,23,40,12]
.  17 | [37,26]     38 | [29,49,57,0,3]    59 | [41,20,38,8,21,30,20]
.  18 | [4,43]      39 | [46,19,48,52,4]   60 | [0,12,12,7,45,10,33]
.  19 | [41,9,1]    40 | [15,9,46,53,7]    61 | [41,32,50,15,6,41,53]
.  20 | [45,52,1]   41 | [1,29,34,46,12]   62 | [41,44,2,23,51,51,26,1]
		

Crossrefs

Cf. A000045, A261585 (row lengths), A261587 (row sums), A261598 (row products), A261606 (left edge), A261607 (right edge).

Programs

  • Haskell
    a261575 n k = a261575_tabf !! n !! k
    a261575_row n = a261575_tabf !! n
    a261575_tabf = [0] : [1] :
       zipWith (add 0) (tail a261575_tabf) a261575_tabf where
       add c (a:as) (b:bs) = y : add c' as bs where (c', y) = divMod (a+b+c) 60
       add c (a:as) [] = y : add c' as [] where (c', y) = divMod (a+c) 60
       add 1   = [1]
       add   _ = []
  • Mathematica
    Reverse[IntegerDigits[Fibonacci[Range[0, 50]], 60], 2] (* Paolo Xausa, Feb 19 2024 *)

A261587 Sum of sexagesimal digits of Fibonacci numbers in base-60 representation.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 30, 26, 56, 23, 20, 43, 63, 47, 51, 98, 31, 70, 101, 112, 95, 89, 125, 96, 103, 81, 125, 29, 95, 65, 101, 48, 149, 138, 169, 130, 122, 134, 138, 154, 174, 151, 148, 122, 152, 156, 131, 169, 241, 233, 179, 235, 178, 236
Offset: 0

Views

Author

Reinhard Zumkeller, Sep 09 2015

Keywords

Comments

a(n) is the sum of the n-th row of table A261575.

Crossrefs

Programs

  • Haskell
    a261587 = sum . a261575_row
    
  • Maple
    a:= n-> add(i, i=convert((<<0|1>, <1|1>>^n)[1, 2], base, 60)):
    seq(a(n), n=0..60);  # Alois P. Heinz, Jan 22 2022
  • Mathematica
    Table[Total[IntegerDigits[n,60]],{n,Fibonacci[Range[0,60]]}] (* Harvey P. Dale, Aug 02 2019 *)
  • PARI
    a(n) = sumdigits(fibonacci(n), 60); \\ Michel Marcus, Jan 22 2022
Showing 1-3 of 3 results.