Comment demo

/*

Demonstrative program about the reliability of the comment made by R. J. Cano at the entry A198960 on Jan 2012.

Instructions:
=============

1) Donwload b198960.txt

2) Delete the offset column. For example in Unix/Linux systems with GNU file utils available try: user@host$ cut -d' ' -f2 b198960.txt > w.txt

3) Run this PARI/GP script. You never should be in the output the banner "The statement about a198960 is wrong!!". (Please first ensure to have allocated enough memory)

*/

default(echo,1);
w=readvec("w");
v=vector(#w-1,k,w[k+1]); \\ Delete the first term a(1)=2;
u=vector(#v,k,(v[k]-26)/6); \\ Convert into "y" parameter of (6*y+26 == 3*9^n-1) each case;
s=vector(#u-1,k,u[k+1]-u[k]); \\ Take the first differences;
print("Thirty-six is: ",s[1]); \\ Consistency checking;
r=vector(#s-1,k,s[k+1]/s[k]); \\ Compute the ratios between each pair of terms.
r/=9; \\ PARI/GP does it like a human.
if(#r==sum(j=1,#r,r[j]),print("Test approved for the given b-file."),print("The statement about a198960 is wrong!!"));
quit();