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A030988
5-automorphic numbers: final digits of 5n^2 agree with n.
1
5, 25, 125, 8125, 78125, 578125, 2578125, 42578125, 642578125, 3642578125, 83642578125, 983642578125, 1983642578125, 51983642578125, 251983642578125, 1251983642578125, 51251983642578125
OFFSET
1,1
COMMENTS
a(n) is the unique positive integer less than 10^n such that a(n) is divisible by 5^n and 5*a(n) - 1 is divisible by 2^n. - Eric M. Schmidt, Aug 18 2012
PROG
(Sage) [crt(inverse_mod(5, 2^n), 0, 2^n, 5^n) for n in range(1, 1001)] # Eric M. Schmidt, Aug 18 2012
CROSSREFS
Sequence in context: A306570 A061835 A321288 * A173260 A080516 A033141
KEYWORD
nonn,base
STATUS
approved