|
|
A077543
|
|
Smallest n-digit composite palindrome.
|
|
0
|
|
|
4, 22, 111, 1001, 10001, 100001, 1000001, 10000001, 100000001, 1000000001, 10000000001, 100000000001, 1000000000001, 10000000000001, 100000000000001, 1000000000000001, 10000000000000001, 100000000000000001
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
a = {4, 22}; Do[k = 10^n; While[d = IntegerDigits[k]; p = FromDigits[ Join[d, Reverse[Drop[d, -1]]]]; PrimeQ[p], k++ ]; a = Append[a, p]; k = 10^n; While[d = IntegerDigits[k]; p = FromDigits[ Join[d, Reverse[d]]]; PrimeQ[p], k++ ]; a = Append[a, p], {n, 1, 8}]; a
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|