[seqfan] Re: ***SPAM*** Occurrences of a(n-1)
Robert FERREOL
robert.ferreol at gmail.com
Mon Oct 7 15:53:38 CEST 2019
Le 29/09/2019 à 08:11, Ali Sada via SeqFan a écrit :
> Hi Everyone,
>
>
> I am studying the sequencesbelow. They count the occurrences of a(n-1.) Each sequence starts with a natural number(m.)
>
>
>
> If we start with a(1)=1 we get:
>
> 1,1,2,1,3,1,4,1,5,1,6,….
>
>
> Each sequencebecomes “periodic” at n=1+m^2. The period is 2m long, and we can find its termswith a simple mod function.
>
>
> I put these sequences in an array, where each column is a sequence starting with 1,2,3,…etc.
>
> https://justpaste.it/6eu84
>
>
> I would really appreciate it if you could recommend any materials about this array.
More precisely, a(m**2+1+2*m*k)=m, a(m**2+1+2*m*k+2*q)=q ,
a(m**2+1+2*m*k+2*q+1)=m+k+1.
A python program (my sequence begin with a(0)=1 , not a(1)=1, python
prefers)
import numpy as np
N=100
T=np.zeros((N+1,N+1),int)
for i in range(N+1):
T[i,0]=i
for n in range(1,N+1):
L=[T[i,j] for j in range(n)]
T[i,n]=L.count(T[i,n-1])
T
As a function, valid for n>=m**2 :
def a(m,n):
k=(n-m**2)//(2*n0);r=(n-m**2)%(2*m)
q=r//2;s=r%2
if s==1:
return(m+k+1)
else:
if q==0:
return(m)
else:
return(q)
--
ROBERT FERRÉOL
6, Rue des Annelets 75019 PARIS
01 42 41 91 98
http://mapage.noos.fr/r.ferreol
https://www.facebook.com/mathcurve
maths, ex mpsi Fénelon Paris
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