A225450 10-adic integer x such that x^7 == (2*(10^n-1)/9)+1 mod 10^n for all n.

7, 6, 3, 4, 0, 1, 9, 6, 8, 0, 7, 7, 0, 7, 5, 0, 6, 8, 6, 0, 5, 9, 2, 5, 6, 3, 2, 1, 3, 5, 3, 1, 8, 2, 2, 8, 6, 1, 1, 9, 8, 2, 1, 5, 3, 9, 6, 9, 8, 9, 9, 7, 1, 9, 7, 5, 6, 5, 1, 7, 0, 7, 6, 4, 4, 5, 8, 6, 4, 6, 8, 9, 2, 9, 8, 8, 3, 2, 0, 0, 1, 8, 2, 7, 9, 1, 5, 8, 6, 8, 2, 5, 6, 4, 6, 2, 9, 3, 5, 7

Offset

1,1

Comments

This is the 10's complement of A225441.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

7^7 == 3 (mod 10).
67^7 == 23 (mod 100).
367^7 == 223 (mod 1000).
4367^7 == 2223 (mod 10000).
4367^7 == 22223 (mod 100000).
104367^7 == 222223 (mod 1000000).

Maple

op([1, 3], padic:-evalp(RootOf(x^7-7/9, x), 10, 202)); # Robert Israel, Feb 05 2019

Prog

(PARI) n=0; for(i=1, 100, m=(2*(10^i-1)/9)+1; for(x=0, 9, if(((n+(x*10^(i-1)))^7)%(10^i)==m, n=n+(x*10^(i-1)); print1(x", "); break)))

Crossrefs

Cf. A225441.

Sequence in context: A019908 A021135 A198374 * A238239 A199437 A021571

Adjacent sequences: A225447 A225448 A225449 * A225451 A225452 A225453

Keyword

nonn,base

Author

Aswini Vaidyanathan, May 11 2013

Status

approved