[seqfan] Another variation with a vertical cut

Eric Angelini Eric.Angelini at kntv.be
Wed Jul 2 17:27:05 CEST 2014


Hello SeqFans,
Could someone please check? And comment -- if of interest?
Many thanks! I guess this is a nice (?) variation on the
recent https://oeis.org/A243357
> Lexicographically earliest sequence with property that
  if a vertical line is drawn between any pair of adjacent
  digits p and q, the number Z formed by the p digits to
  the left of the line is divisible by p.

S = 1,2,3,11,5,6,4,8,12,13,15,21,22,24,17,16,25,19,7,23,27,...

Example:
a) draw a line between 6 and 4, for instance -- thus p = 6:
   S = 1,2,3,11,5,6|,4,
b) concatenate the last 6 digits before the line (to get Z):
   Z = 231156
c) Z/p is an integer (indeed, Z/6 = 38526)

We have here (if I'm not wrong):

         Z / p = integer   (Z ends in p and has digit-length p)
         1 / 1 = 1
        12 / 2 = 6
       123 / 3 = 41
         1 / 1 = 1
         1 / 1 = 1
     23115 / 5 = 4623
    231156 / 6 = 38526
      1564 / 4 = 391
  23115648 / 8 = 2889456
         1 / 1 = 1
        12 / 2 = 6
         1 / 1 = 1
       213 / 3 = 71
         1 / 1 = 1
     21315 / 5 = 4263
        52 / 2 = 26
         1 / 1 = 1
        12 / 2 = 6
        22 / 2 = 11
        22 / 2 = 11
      2224 / 4 = 556
         1 / 1 = 1
   1222417 / 7 = 174631
         1 / 1 = 1
    241716 / 6 = 40286
        62 / 2 = 31
     71625 / 5 = 14325
         1 / 1 = 1
417162519 / 9 = 46351391
   1625197 / 7 = 232171
        72 / 2 = 36
       723 / 3 = 241
        32 / 2 = 16
   1972327 / 7 = 281761
...

S is infinite, of course, as it can always be extended
with an integer (not yet present) having only 1's.

Best,
É.








More information about the SeqFan mailing list