A154530 Primes that are a concatenation of 2*k and 2*k+1 or 2*k and 2*k-1 for some k.

23, 43, 67, 89, 109, 1213, 2221, 2423, 3433, 3637, 4241, 4243, 5051, 5657, 5857, 6263, 6869, 7069, 7877, 7879, 8081, 8887, 9091, 9293, 9697, 10099, 102101, 102103, 108107, 108109, 112111, 114113, 120121, 124123, 126127, 138139, 148147, 150151

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n=1..10153

Example

2*1=2, 2*1+1=3, and 23 the concatenation of 2 and 3 is prime, so a(1)=23

Prog

(Haskell)
a154530 n = a154530_list !! (n-1)
a154530_list = filter ((== 1) . a010051') a248378_list
-- Reinhard Zumkeller, Jun 27 2015

Crossrefs

Cf. A133986, A154531, A328903.

Cf. A010051, subsequence of A248378.

Sequence in context: A306085 A037137 A340136 * A156979 A281226 A158283

Adjacent sequences: A154527 A154528 A154529 * A154531 A154532 A154533

Keyword

nonn,base

Author

Pierre CAMI, Jan 11 2009

Extensions

Edited by Charles R Greathouse IV, Apr 28 2010

Status

approved