OFFSET
1,2
COMMENTS
J. Brennen found the (prime) term 252717253.
LINKS
Jack Brennen, Table of n, a(n) for n = 1..66
Woodhodgson, Digit block repetition in prime squares, Yahoo! group primenumbers, Aug 28 2012.
Woodhodgson, Jack Brennen, Maximilian Hasler, Digit block repetition in prime squares, digest of 7 messages in primenumbers Yahoo group, Aug 28 - Aug 30, 2012.
EXAMPLE
The squares of n=1,2,3 are < 10 and thus of the form xyx, where x is an empty string.
a(4) = 11 since 11^2 = 121 = xyx with x=1 and y=2.
a(7) = 173 since 173^2 = 29929 = xyx with x=29 and y=9.
PROG
(PARI) {t=1; m=3; for(n=1, 1e9, n>m & (m=sqrt((n=t*=10)^2*10)) & next; [.1, -1]*divrem(n^2, t)\1 || print1(n", "))}
CROSSREFS
KEYWORD
nonn,base
AUTHOR
M. F. Hasler, Aug 28 2012
EXTENSIONS
a(17)-a(31) from Donovan Johnson, Aug 28 2012
STATUS
approved