

A067006


Smallest number for which the totient is divisible by the nth nontotient number, that is, the nth term of A007617.


0



7, 11, 29, 19, 23, 53, 29, 31, 103, 191, 43, 47, 101, 53, 81, 59, 311, 67, 103, 71, 149, 191, 79, 83, 173, 181, 283, 197, 101, 103, 107, 121, 229, 709, 367, 311, 127, 131, 269, 137, 139, 569, 293, 149, 151, 229, 463, 317, 163, 167, 1021, 173, 349, 179, 181, 547
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..56.


FORMULA

a(n) = min_{x : mod(x, A007617(n)) = 0}. For all nontotient numbers x, q*x+1 is prime with large enough q and a divisor of phi(q*x+1) = q*x is x, the selected nontotient number.


EXAMPLE

14 = A007617(7) is not totient of any other number, but phi(29) = 28 is divisible with 14 and 29 is the smallest number of which the totient is a multiple of 14, so a(7)=29.


CROSSREFS

Cf. A000010, A007617, A066674A066678, A067005.
Sequence in context: A002810 A045736 A158807 * A136020 A076304 A122560
Adjacent sequences: A067003 A067004 A067005 * A067007 A067008 A067009


KEYWORD

nonn


AUTHOR

Labos Elemer, Dec 22 2001


STATUS

approved



