OFFSET
1,2
COMMENTS
The final digit determines the number by an obvious algorithm (see PARI program), hence the sequence has exactly nine terms (for final digit 1, ..., 9), self-concatenations being excluded. - Klaus Brockhaus, Apr 24 2003
REFERENCES
J. J. Clessa, Micropuzzles, Pan Books, 1983, p. 44 (puzzle 5).
M. J. Halm, More Sequences, Mpossibilities 83, April 2003.
C. A. Pickover, Wonders of Numbers, p. 193.
LINKS
M. J. Halm, Sequences
C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," Zentralblatt review
EXAMPLE
a(1) = 102564 because 102564*4 = 410256.
PROG
(PARI) {f(digit)=local(v, m, k, c, s); v=""; m=0; k=digit; c=0; while(m!=digit, v=concat(k, v); m=digit*k+c; s=divrem(m, 10); c=s[1]; k=s[2]); eval(v)}
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Michael Joseph Halm, Apr 20 2003
EXTENSIONS
Edited and missing terms added by Klaus Brockhaus, Apr 22 2003
STATUS
approved