A118965 -id:A118965 - cp's OEIS frontend

A128924 T(n,m) is the number of m's in the fundamental period of Fibonacci numbers mod n.

1, 1, 2, 2, 3, 3, 1, 3, 1, 1, 4, 4, 4, 4, 4, 2, 6, 3, 4, 3, 6, 2, 4, 2, 1, 1, 2, 4, 2, 3, 2, 1, 0, 3, 0, 1, 2, 5, 2, 2, 2, 2, 2, 2, 5, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 1, 3, 2, 1, 0, 1, 0, 0, 1, 0, 1, 2, 5, 2, 2, 1, 5, 0, 1, 1, 2, 2, 1, 4, 4, 2, 2, 0, 4, 0, 0, 4, 0, 2, 2, 4, 2, 8, 2, 2, 1, 4, 4, 4, 4, 4, 1, 2, 2, 8

Offset: 1

R. J. Mathar, Apr 25 2007

T(n,m) is the triangle read by rows, 0<=m

A118965 and A066853 give numbers of zeros and nonzeros in n-th row, respectively. - Reinhard Zumkeller, Jan 16 2014

			{F(k) mod 4} has fundamental period (0,1,1,2,3,1), see A079343, with
T(4,0)=1 zero, T(4,1)=3 ones, T(4,2)=1 two's, T(4,3)=1 three's. The triangle starts
1,
1, 2,
2, 3, 3,
1, 3, 1, 1,
4, 4, 4, 4, 4,
2, 6, 3, 4, 3, 6,
2, 4, 2, 1, 1, 2, 4,
2, 3, 2, 1, 0, 3, 0, 1,
2, 5, 2, 2, 2, 2, 2, 2, 5,
4, 8, 4, 8, 4, 8, 4, 8, 4, 8,
1, 3, 2, 1, 0, 1, 0, 0, 1, 0, 1,
2, 5, 2, 2, 1, 5, 0, 1, 1, 2, 2, 1,
4, 4, 2, 2, 0, 4, 0, 0, 4, 0, 2, 2, 4,
2, 8, 2, 2, 1, 4, 4, 4, 4, 4, 1, 2, 2, 8,
2, 3, 3, 2, 3, 3, 2, 3, 3, 2, 3, 3, 2, 3, 3,
2, 3, 4, 1, 0, 3, 0, 1, 2, 3, 0, 1, 0, 3, 0, 1,
4, 4, 2, 2, 4, 2, 0, 0, 2, 2, 0, 0, 2, 4, 2, 2, 4,

Reinhard Zumkeller, Rows n = 1..125 of triangle, flattened
G. Darvasi and St. Eckmann, Zur Verteilung der Reste der Fibonacci-Folge modulo 5c, Elemente der Mathematik 50 (1995) pp. 76-80.

Cf. A053029, A053030, A053031, A001175 (row sums), A001176 (1st column).

import Data.List (group, sort)
a128924 n k = a128924_tabl !! (n-1) !! (k-1)
a128924_tabl = map a128924_row [1..]
a128924_row 1 = [1]
a128924_row n = f [0..n-1] $ group $ sort $ g 1 ps where
   f []     _                            = []
   f (v:vs) wss'@(ws:wss) | head ws == v = length ws : f vs wss
                          | otherwise    = 0 : f vs wss'
   g 0 (1 : xs) = []
   g _ (x : xs) = x : g x xs
   ps = 1 : 1 : zipWith (\u v -> (u + v) `mod` n) (tail ps) ps
-- Reinhard Zumkeller, Jan 16 2014

A128924 := proc(m,h)
    local resul,k,M ;
    resul :=0 ;
    for k from 0 to A001175(m)-1 do
        M := combinat[fibonacci](k) mod m ;
        if M = h then
            resul := resul+1 ;
        end if ;
    end do;
    resul ;
end proc:
seq(seq(A128924(m,h),h=0..m-1),m=1..17) ;

A001175[1] = 1; A001175[n_] := For[k = 1, True, k++, If[Mod[Fibonacci[k], n] == 0 && Mod[Fibonacci[k+1], n] == 1, Return[k]]]; T[m_, h_] := Module[{resul, k, M}, resul = 0; For[k = 0, k <= A001175[m]-1, k++, M = Mod[Fibonacci[k], m]; If[ M == h, resul++]]; Return[resul]]; Table[T[m, h], {m, 1, 17}, {h, 0, m-1}] // Flatten (* Jean-François Alcover, Feb 11 2015, after Maple code *)

T(n,n) = A235715(n). - Reinhard Zumkeller, Jan 17 2014

A137751 a(n) = number of missing residues in the Fibonacci sequence mod the n-th prime number.

Original entry on oeis.org

0, 0, 0, 0, 4, 4, 4, 7, 4, 19, 12, 8, 22, 10, 32, 16, 22, 36, 16, 27, 16, 30, 20, 72, 28, 66, 24, 74, 60, 80, 30, 49, 28, 106, 88, 114, 44, 40, 40, 36, 67, 119, 72, 44, 48, 183, 181, 54, 56, 149, 212, 90, 138, 94, 64, 178, 156, 102

Offset: 1

Casey Mongoven, Feb 10 2008

nonn

			The 5th prime number is 11. The Fibonacci sequence mod 11 is {0,1,1,2,3,5,8,2,10,1,0,1,...} - a periodic sequence. There are 4 residues which do not occur in this sequence, namely {4,6,7,9}. So a(5) = 4.

Alois P. Heinz, Table of n, a(n) for n = 1..10000
Casey Mongoven, Absent Residues Primes no. 1; electro-acoustic music created with this sequence.

Cf. A118965, A137750, A000045.

A223487 Number of missing residues in Lucas sequence mod n.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 2, 0, 2, 4, 2, 1, 0, 8, 5, 1, 7, 7, 10, 8, 8, 4, 10, 13, 2, 0, 8, 19, 16, 12, 10, 16, 14, 22, 21, 9, 25, 15, 30, 22, 16, 10, 24, 28, 25, 32, 31, 12, 26, 20, 16, 9, 25, 39, 28, 28, 38, 22, 42, 33, 41, 30, 22, 49, 32, 16, 42, 36, 44, 27, 55

Offset: 1

Casey Mongoven, Mar 20 2013

nonn

The Lucas numbers mod n for any n are periodic - see A106291 for period lengths.

T. D. Noe, Table of n, a(n) for n = 1..1000
D. D. Wall, Fibonacci series modulo m, Amer. Math. Monthly, 67 (1960), 525-532.

Cf. A118965.

pisano[n_] := Module[{a = {2, 1}, a0, k = 0, s, t}, If[n == 1, 1, a0 = a; t = a; While[k++; s = Mod[Plus @@ a, n]; AppendTo[t, s]; a[[1]] = a[[2]]; a[[2]] = s; a != a0]; t]]; Join[{0, 0}, Table[u = Union[pisano[n]]; mx = Max[u]; Length[Complement[Range[0, mx], u]], {n, 3, 100}]] (* T. D. Noe, Mar 22 2013 *)

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A128924 T(n,m) is the number of m's in the fundamental period of Fibonacci numbers mod n.

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A137751 a(n) = number of missing residues in the Fibonacci sequence mod the n-th prime number.

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A223487 Number of missing residues in Lucas sequence mod n.

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