A089331 a(1) = 1; for n>1, a(n) = smallest power of 2 not included earlier such that the (n>1) concatenation a(n), a(n-1), ...a(2), a(1) is a prime.

1, 4, 2, 4096, 8, 16, 524288, 18446744073709551616, 3064991081731777716716694054300618367237478244367204352, 268435456, 14474011154664524427946373126085988481658748083205070504932198000989141204992

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Example

41,241,4096241, etc. are primes.

Crossrefs

Sequence in context: A016518 A118202 A277578 * A125856 A057110 A073275

Adjacent sequences: A089328 A089329 A089330 * A089332 A089333 A089334

Keyword

base,nonn

Author

Amarnath Murthy, Nov 04 2003

Extensions

More terms from David Wasserman, Sep 13 2005

Status

approved