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A104039 Number of primitive roots modulo (p(n))^2, where p(n) is n-th prime. 0
1, 2, 8, 12, 40, 48, 128, 108, 220, 336, 240, 432, 640, 504, 1012, 1248, 1624, 960, 1320, 1680, 1728, 1872, 3280, 3520, 3072, 4000, 3264, 5512, 3888, 5376, 4536, 6240, 8704, 6072, 10656, 6000, 7488, 8748, 13612, 14448, 15664, 8640, 13680, 12288, 16464 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

I. Niven, H. S. Zuckerman & H. L. Montgomery, An Introduction to the Theory of Numbers, 5-th Edit. pp. 102 John Wiley NY 1991.

FORMULA

a(n) = (p(n)-1)*phi((p(n)-1) = A006093(n)*A000010(A006093(n))= A006093(n)*A008330(n).

MAPLE

with(numtheory): for p from 1 to 100 do printf(`%d, `, (ithprime(p)-1)*phi(ithprime(p)-1)) od: (Sellers)

CROSSREFS

Sequence in context: A078541 A135443 A143231 * A083546 A013190 A176968

Adjacent sequences:  A104036 A104037 A104038 * A104040 A104041 A104042

KEYWORD

nonn

AUTHOR

Lekraj Beedassy (blekraj(AT)yahoo.com), Mar 31 2005

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Apr 10 2005

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Last modified February 18 00:14 EST 2012. Contains 206085 sequences.