

A030984


2automorphic numbers: final digits of 2*n^2 agree with n.


1



8, 88, 688, 4688, 54688, 554688, 3554688, 93554688, 893554688, 893554688, 40893554688, 40893554688, 40893554688, 70040893554688, 870040893554688, 1870040893554688, 71870040893554688, 871870040893554688
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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 2^n and 2*a(n)  1 is divisible by 5^n.  Eric M. Schmidt, Aug 18 2012


LINKS

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


PROG

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


CROSSREFS

Sequence in context: A299671 A299749 A300263 * A109021 A271939 A043043
Adjacent sequences: A030981 A030982 A030983 * A030985 A030986 A030987


KEYWORD

nonn,base,changed


AUTHOR

Eric W. Weisstein


STATUS

approved



