A078830 Numbers having in binary representation exactly one binary substring representing a prime.

2, 3, 4, 8, 9, 16, 32, 33, 64, 65, 128, 129, 256, 512, 513, 1024, 1025, 2048, 2049, 4096, 4097, 8192, 8193, 16384, 16385, 32768, 32769, 65536, 131072, 131073, 262144, 262145, 524288, 524289, 1048576, 1048577, 2097152, 2097153, 4194304, 4194305

Offset: 1

Author

Reinhard Zumkeller, Dec 08 2002

Keywords

• nonn
• base

Comments

A078827(a(n)) = 1; subsequence of A078829 and of A078831;

for k>2 also floor(a(k)/2) belongs to the sequence.

Examples

			p=2 -> '10' is the only prime contained exactly once in 2^k, k>0.
		

Crossrefs

Cf. A078827, A078829, A007088, A000079, A048578.

Extensions

Extended by Ray Chandler, Nov 03 2008