

A030991


7automorphic numbers ending in 5: final digits of 7n^2 agree with n.


1



5, 75, 375, 4375, 84375, 984375, 8984375, 58984375, 458984375, 5458984375, 45458984375, 845458984375, 2845458984375, 22845458984375, 322845458984375, 2322845458984375, 22322845458984375
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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 7a(n)  1 is divisible by 2^n.  Eric M. Schmidt, Aug 18 2012


LINKS

Eric M. Schmidt, Table of n, a(n) for n = 1..1000
Index entries for sequences related to automorphic numbers
Index entries for sequences related to final digits of numbers
Eric Weisstein's World of Mathematics, Automorphic Number


PROG

(Sage) [crt(inverse_mod(7, 2^n), 0, 2^n, 5^n) for n in range(1, 1001)] # Eric M. Schmidt, Aug 18 2012


CROSSREFS

Sequence in context: A156703 A285452 A048350 * A216093 A151752 A127212
Adjacent sequences: A030988 A030989 A030990 * A030992 A030993 A030994


KEYWORD

nonn,base


AUTHOR

Eric W. Weisstein


STATUS

approved



