|
| |
|
|
A045777
|
|
a(1)=1, a(2)=2; thereafter successive products of pairs of digits make further digits.
|
|
2
|
|
|
|
1, 2, 2, 4, 8, 3, 2, 2, 4, 6, 4, 8, 2, 4, 2, 4, 3, 2, 1, 6, 8, 8, 8, 1, 2, 6, 2, 6, 4, 8, 6, 4, 6, 4, 8, 2, 1, 2, 1, 2, 1, 2, 2, 4, 3, 2, 4, 8, 2, 4, 2, 4, 2, 4, 3, 2, 1, 6, 2, 2, 2, 2, 2, 2, 4, 8, 1, 2, 6, 8, 3, 2, 1, 6, 8, 8, 8, 8, 8, 1, 2, 6, 2, 6, 1, 2, 4, 4, 4, 4, 4, 8, 3, 2, 8, 2, 1, 2, 4, 8, 2, 4, 6, 2, 6
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
The numbers 0, 5, 7, and 9 never appear, but arbitrarily long sequences of 8's appear.
|
|
|
REFERENCES
|
Erich Friedman, Puzzles of the Week, http://www2.stetson.edu/~efriedma/mathpuzzle/
|
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n = 1..15212
|
|
|
EXAMPLE
|
1*2=2 2*2=4 2*4=8 4*8=32 8*3=24...
|
|
|
MATHEMATICA
|
t = {1, 2}; Do[ t = Join[t, IntegerDigits[t[[n-1]] t[[n-2]]]], {n, 3, 100}]; t
|
|
|
CROSSREFS
|
Sequence in context: A131199 A112059 A093094 * A136534 A121175 A183397
Adjacent sequences: A045774 A045775 A045776 * A045778 A045779 A045780
|
|
|
KEYWORD
|
easy,nonn,base
|
|
|
AUTHOR
|
Erich Friedman
|
|
|
STATUS
|
approved
|
| |
|
|
