

A306451


Noncoprime pseudoprimes or primes to base 3: numbers k that are multiples of 3 and are such that k divides 3^k  3.


2



3, 6, 66, 561, 726, 7107, 8205, 8646, 62745, 100101, 140097, 166521, 237381, 237945, 566805, 656601, 876129, 1053426, 1095186, 1194285, 1234806, 1590513, 1598871, 1938021, 2381259, 2518041, 3426081, 4125441, 5398401, 5454681, 5489121, 5720331, 5961441
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OFFSET

1,1


COMMENTS

Numbers of the form 3*m such that 3^(3*m1) == 1 (mod m).
The squarefree terms are listed in A306450.


LINKS



FORMULA

66 is a term because 66 divides 3^66  3 = 3*(3^65  1) = 3*(3^5  1)*(3^60 + 3^55 + ... + 3^5 + 1) and 66 is divisible by 3.


PROG

(PARI) forstep(n=3, 1e7, 3, if(Mod(3, n)^n==3, print1(n, ", ")))


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



