Voozh

A030993

8-automorphic numbers: final digits of 8*n^2 agree with n.

2, 72, 672, 8672, 88672, 388672, 3388672, 23388672, 223388672, 223388672, 10223388672, 510223388672, 7510223388672, 67510223388672, 967510223388672, 7967510223388672, 67967510223388672

(list; graph; refs; listen; history; text; internal format)

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 8*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

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

(SageMath) [crt(0, inverse_mod(8, 5^n), 2^n, 5^n) for n in range(1, 1001)] # Eric M. Schmidt, Aug 18 2012

CROSSREFS

Sequence in context: A272757 A187707 A163274 * A283568 A070775 A157061

Adjacent sequences: A030990 A030991 A030992 * A030994 A030995 A030996

KEYWORD

nonn,base

AUTHOR

Eric W. Weisstein

STATUS

approved

URL: https://oeis.org/A030993

⇱ A030993 - OEIS