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A112674 Numbers of the form (2^(i*j)-1)/((2^i-1)*(2^j-1)) where gcd(i,j) = 1. 0
1, 3, 11, 39, 43, 151, 171, 683, 2255, 2359, 2731, 9399, 10923, 43691, 140911, 149943, 174763, 549791, 599479, 699051, 2796203, 8727391, 8965359, 9588151, 11184811, 38350263, 44739243, 139090655, 178956971, 549687103, 572942063, 613576119 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

C. L. Chen, R. T. Chien and C. K. Liu, On the binary representation form of certain integers, SIAM J. Appl. Math. 26 (1974), 283-293.

LINKS

Table of n, a(n) for n=1..32.

MATHEMATICA

t = {1}; Do[a = (2^(i*j) - 1)/((2^i - 1)*(2^j - 1)); If[ GCD[i, j] == 1 && 1 < a < 10^9, AppendTo[t, a]], {i, 31}, {j, i - 1}]; Sort@t (* Robert G. Wilson v *)

CROSSREFS

Sequence in context: A178624 A027528 A192528 * A064086 A089579 A227638

Adjacent sequences:  A112671 A112672 A112673 * A112675 A112676 A112677

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 30 2005

EXTENSIONS

More terms from Robert G. Wilson v, Dec 31 2005

STATUS

approved

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Last modified September 2 07:56 EDT 2014. Contains 246326 sequences.