

A332055


Tower of 8's modulo n.


2



0, 0, 1, 0, 1, 4, 1, 0, 1, 6, 3, 4, 1, 8, 1, 0, 1, 10, 11, 16, 1, 14, 6, 16, 6, 14, 19, 8, 20, 16, 8, 0, 25, 18, 1, 28, 26, 30, 1, 16, 10, 22, 35, 36, 1, 6, 25, 16, 8, 6, 1, 40, 28, 46, 36, 8, 49, 20, 4, 16, 34, 8, 1, 0, 1, 58, 24, 52, 52, 36, 8, 64, 8, 26, 31
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OFFSET

1,6


COMMENTS

a(n) = (8^(8^(8^(8^ ... )))) mod n, provided sufficient 8's are in the tower such that adding more doesn't affect the value of a(n).


LINKS

Table of n, a(n) for n=1..75.


FORMULA

a(n) = 8^(A000010(n) + a(A000010(n))) mod n.
a(n) = (8^^k) mod n, if n < A246496(k), where ^^ is Knuth's doublearrow notation.


PROG

(PARI) a(n) = {my(b, c=0, d=n, k=1, x=1); while(k==1, z=x; y=1; b=1; while(z>0, while(y<z, d=eulerphi(d); y++); b=8^bfloor((8^b1)/d)*d; z=z1; y=1; d=n); if(c==b, k=0); c=b; x++); b%n; }


CROSSREFS

Cf. A240162, A245970, A245971, A245972, A245973, A245974, A246496, A332054.
Sequence in context: A010639 A035588 A318623 * A073027 A278986 A292159
Adjacent sequences: A332052 A332053 A332054 * A332056 A332057 A332058


KEYWORD

nonn


AUTHOR

Jinyuan Wang, Mar 04 2020


STATUS

approved



