Cullen Number
A number of the form
The first few are 3, 9, 25, 65, 161, 385, ... (Sloane's A002064). The only Cullen numbers
for 
which arePrime are for 
, 141, 4713, 5795, 6611, 18496, 32292, 32469, 59656, 90825, 262419, ... (Sloane's A005849; Ballinger). Cullennumbers are Divisible by 
if 
is a Prime of the form 
.See also Cunningham Number, Fermat Number, Sierpinski Number of the First Kind,Woodall Number
References
Ballinger, R. ``Cullen Primes: Definition and Status.'' http://vamri.xray.ufl.edu/proths/cullen.html. Guy, R. K. ``Cullen Numbers.'' §B20 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, p. 77, 1994. Keller, W. ``New Cullen Primes.'' Math. Comput. 64, 1733-1741, 1995. Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/cullen. Ribenboim, P. The New Book of Prime Number Records. New York: Springer-Verlag, pp. 360-361, 1996. Sloane, N. J. A. SequencesA002064/M2795and A005849/M5401in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
- Augmented Dodecahedron
- Augmented Hexagonal Prism
- Augmented Pentagonal Prism
- Augmented Polyhedron
- Augmented Sphenocorona
- Augmented Triangular Prism
- Augmented Tridiminished Icosahedron
- Augmented Truncated Cube
- Augmented Truncated Dodecahedron
- Augmented Truncated Tetrahedron
- Aureum Theorema
- Aurifeuillean Factorization
- Ausdehnungslehre
- Authalic Latitude
- Autocorrelation
- Automorphic Function
- Automorphic Number
- Automorphism
- Automorphism Group
- Autonomous
- Autoregressive Model
- Auxiliary Circle
- Auxiliary Latitude
- Auxiliary Triangle
- Average