A183613 a(n) = 3^^(n+1) modulo 10^n.

7, 87, 387, 5387, 95387, 195387, 4195387, 64195387, 464195387, 2464195387, 62464195387, 262464195387, 7262464195387, 27262464195387, 627262464195387, 5627262464195387, 75627262464195387, 575627262464195387, 4575627262464195387, 4575627262464195387

Offset: 1

Author

Max Alekseyev, Sep 08 2011

Keywords

• nonn

Comments

Backward concatenation of A133613.

For all m>n, 3^^m == 3^^(n+1) (mod 10^n). Hence, each term represents the tailing decimal digits of 3^^m for all sufficiently large m.

References

• M. Ripà, La strana coda della serie n^n^...^n, Trento, UNI Service, Nov 2011, p. 11-12, 69-78. ISBN 978-88-6178-789-6.

Links

• J. Jimenez Urroz and J. Luis A. Yebra, On the equation a^x == x (mod b^n), J. Int. Seq. 12 (2009) #09.8.8.

Formula

For n>1, a(n) = 3^a(n-1) mod 10^n.