A246557 Numbers n with an even number of digits such that the product of the numbers formed by successively deleting pairs of digits from the ends of n is equal to n.

116955, 125000, 228177, 375000, 495248

Offset

1,1

Comments

The sequence is finite.

If the number of digits of n is odd then the analogous product can never equal n.

Links

Table of n, a(n) for n=1..5.

Example

116955 is in the sequence because we get 1695 and then 69, whose product is 116955.

Maple

lst:={}:
for a from 1 to 99 do:
  for b from 1 to 9 do:
   for c from 0 to 9 do:
      x1:=a*10+c:x:=b*10^length(x1)+x1:
z:=a*x:l:=length(z) :
u:=(z-irem(z, 10))/10: v0:=irem(u, 10^(l-2)):
       if v0 = x then lst:=lst union {z}:
else
fi:
   od:
  od:
od:
print(lst):

Crossrefs

Sequence in context: A156417 A156865 A233681 * A289911 A206204 A251953

Adjacent sequences: A246554 A246555 A246556 * A246558 A246559 A246560

Keyword

nonn,fini,full,base

Author

Michel Lagneau, Nov 15 2014

Status

approved