|
|
A081463
|
|
Numbers which when multiplied by their final digit have products with same digital sequence except that last is first. Numbers obtained by concatenating a term any number of times with itself also have the defining property and are omitted.
|
|
3
|
|
|
1, 102564, 1012658227848, 105263157894736842, 1014492753623188405797, 1034482758620689655172413793, 102040816326530612244897959183673469387755, 10112359550561797752808988764044943820224719, 1016949152542372881355932203389830508474576271186440677966
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
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
|
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
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|