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A092188 a(n) = smallest positive integer m such that 2^3^4^5^...^n == m (mod n). 5
2, 2, 4, 2, 2, 1, 8, 8, 2, 2, 8, 5, 8, 2, 16, 2, 8, 18, 12, 8, 2, 16, 8, 2, 18, 26, 8, 11, 2, 2, 32, 2, 2, 22, 8, 31, 18, 5, 32, 2, 8, 27, 24, 17, 16, 8, 32, 43, 2, 2, 44, 45, 26, 2, 8, 56, 40, 47, 32, 33, 2, 8, 64, 57, 2, 5, 36, 62, 22, 60, 8, 1, 68, 2, 56, 57, 44, 8, 32, 80, 2, 2, 8, 2, 70 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Max Alekseyev, Table of n, a(n) for n = 2..1000

R. Munafo, Smallest positive integer m such that 2^3^4^5^...^n == m mod n

FORMULA

a(n) = n if n is a power of 2; otherwise a(n) = (2^3^4^5^...^n) mod n = A213013(n). [From Max Alekseyev, Jun 02 2012]

EXAMPLE

2^3^4^5 = 2^3^1024. But 3 == -1 (mod 4), so 3^1024 == 1 (mod 4), so 2^3^1024 == 2^1 (mod 5) since 2^4 == 1 (mod 5). Thus a(5) = 2.

CROSSREFS

Sequence in context: A261872 A021450 A239675 * A097884 A094818 A114233

Adjacent sequences:  A092185 A092186 A092187 * A092189 A092190 A092191

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane, following a suggestion of J. H. Conway, Apr 02 2004

EXTENSIONS

More terms from Robert Munafo, Apr 11 2004

STATUS

approved

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Last modified July 20 07:21 EDT 2017. Contains 289624 sequences.