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A219175 a(n) = n mod lambda(n) where lambda is the Carmichael function (A002322). 5
0, 0, 1, 0, 1, 0, 1, 0, 3, 2, 1, 0, 1, 2, 3, 0, 1, 0, 1, 0, 3, 2, 1, 0, 5, 2, 9, 4, 1, 2, 1, 0, 3, 2, 11, 0, 1, 2, 3, 0, 1, 0, 1, 4, 9, 2, 1, 0, 7, 10, 3, 4, 1, 0, 15, 2, 3, 2, 1, 0, 1, 2, 3, 0, 5, 6, 1, 4, 3, 10, 1, 0, 1, 2, 15, 4, 17, 6, 1, 0, 27, 2, 1, 0, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

COMMENTS

a(n) = A068494(n) for n = 1..14.

a(k) = 1 for k = prime(n) > 2 or k = A002997(n).

a(n) is the smallest k >= 0 such that b^(n-k) == 1 (mod n) for every b coprime to n. - Thomas Ordowski, Jun 30 2017

LINKS

Michel Lagneau, Table of n, a(n) for n = 1..10000

EXAMPLE

a(9) = 3 because lambda(9) = 6 and 9 == 3 mod 6.

MAPLE

with(numtheory):for n from 1 to 100 do: x:=irem(n, lambda(n)): printf(`%d, `, x):od:

MATHEMATICA

Table[Mod[n, CarmichaelLambda[n]], {n, 100}] (* T. D. Noe, Nov 13 2012 *)

PROG

(PARI) a(n)=n%lcm(znstar(n)[2]) \\ Charles R Greathouse IV, Nov 13 2012

CROSSREFS

Cf. A068494, A002322, A002997.

Sequence in context: A062160 A301296 A194703 * A022959 A023445 A291760

Adjacent sequences:  A219172 A219173 A219174 * A219176 A219177 A219178

KEYWORD

nonn

AUTHOR

Michel Lagneau, Nov 13 2012

STATUS

approved

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Last modified June 4 04:39 EDT 2020. Contains 334815 sequences. (Running on oeis4.)